A short multi-branched alkylthio chain strategy enables high-efficiency as-cast organic solar cells via improving solubility and crystallinity
短的多支链烷基硫代链策略通过提高溶解度和结晶度实现高效的铸态有机太阳能电池

Keywords: As-cast organic solar cells, Short multi-alkylthio chains, Solubility, Crystallinity
关键词：铸态有机太阳能电池， 短多烷基硫代链， 溶解度， 结晶度

Abstract:
抽象：

The as-cast devices without any additives or further treatments, hold the greatest potential for the commercialization of non-fullerene acceptor (NFA) organic solar cells (OSCs). However, the trade-off between solubility and crystallinity of NFA molecules critically hinders the power-conversion efficiency (PCE) of as-cast devices, which are significantly lower than those of state-of-the-art OSCs. In this study, we introduced two new BTP-S-series NFAs with outer alkylthio chains, synthesized using the palladium-catalyzed coupling method, to address this issue. In contrast to BTP-S-C12 featured long linear alkylthio chains, BTP-S-DMO, equipped with short multi-branched alkylthio chains (SMBA), exhibits improved solubility, minimal blueshifted light absorption, ameliorated molecular packing, and compacted three-dimensional charge transport networks. In situ spectroscopic characterizations synergistically revealed the enhanced interaction between donor/acceptor molecules and the preferred orientation arrangement of NFAs during the phase transition process based on BTP-S-DMO. The well-defined nanofibrous morphology in the D18:BTP-S-DMO blend film ultimately resulted in exceptional charge transport processes and reduced trap-state density. Consequently, as-cast binary OSCs based on BTP-S-DMO yielded a notable PCE of 18.4%, with a V_oc of 0.85 V, a J_sc of 27.3 mA cm^-2, and an FF of 79.1%, representing the highest PCE reported for as-cast OSCs. This work not only introduces the new SMBA strategy to optimize both solubility and crystallinity but also holds great prospects for improving the photovoltaic performance of OSCs.
无需任何添加剂或进一步处理的铸态器件在非富勒烯受体 （NFA） 有机太阳能电池 （OSC） 的商业化方面具有最大的潜力。然而，NFA 分子的溶解度和结晶度之间的权衡严重阻碍了铸态器件的功率转换效率 （PCE），其功率转换效率 （PCE） 明显低于最先进的 OSC。在这项研究中，我们引入了两个新的具有外烷基硫基链的 BTP-S 系列 NFA，使用钯催化偶联方法合成，以解决这一问题。 与具有长线性烷基硫基链的 BTP-S-C12 相比，配备短多支链烷基硫基链 （SMBA） 的 BTP-S-DMO 表现出更高的溶解度、最小的蓝移光吸收、改善的分子堆积和紧凑的三维电荷传输网络。 原位光谱表征协同揭示了基于 BTP-S-DMO 的相变过程中供体/受体分子之间增强的相互作用以及 NFA 的择优取向排列。D18：BTP-S-DMO 混合膜中明确的纳米纤维形态最终导致了特殊的电荷传输过程和降低的陷阱态密度。因此， 基于 BTP-S-DMO 的铸态二元 OSC 产生了 18.4% 的显着 PCE，V _oc 为 0.85 V，J _sc 为 27.3 mA ^cm-2，FF 为 79。1%，代表铸态 OSC 报告的最高 PCE这项工作不仅引入了新的 SMBA 策略来优化溶解度和结晶度，而且在提高 OSC 的光伏性能方面具有很大的前景。

1. Introduction
1. 引言

Both the scientific and business communities have conducted extensive research into the development of non-fullerene acceptor (NFA) organic solar cells (OSCs) due to their exceptional optoelectrical properties, light weight, mechanical flexibility, semitransparency, and scalability.^[1-4] After the emergence of the Y6 NFA ^[5], a landmark in the A-DA'D-A type derived from the structure of BZIC ^[6], researchers have devoted considerable effort to understanding the correlation between molecular properties, self-assembly structure, materials engineering, and device physics to achieve the power conversion efficiency (PCE) close to 20% for single-junction OSCs.^{[7] [8] [9] [10] [11] [12] [13] [14]} However, these devices require delicate device modification, such as thermal annealing, solvent annealing, or additive engineering.^[2] Even though significant improvements in photovoltaic performance have been accomplished after these subtle regulation approaches, the blend nanomorphology remains in a sub-thermodynamic state, which can affect the device's stability during storage. Thus, the as-cast device without any pre-/post-treatment is a requirement for the genuine commercialization of OSCs.^[15-16] Nevertheless, critical challenges remain to hinder the performance of as-cast OSCs, particularly for NFAs related to the exciton dynamics. At present, the structure of NFAs can be optimized through the use of strong electron-deficient core units, unique fused-ring backbones, and modulation of various side chains. In typical Y-series NFAs, the outer side chains that attach to the β-positions of the thieno[3,2-b]thiophene core are believed to play a crucial part in fine-tuning the intrinsic molecular conformation, crystallinity, and photovoltaic performances. Y-series NFAs that have outer linear chains, such as N3^[17], BTP-4Cl^[18], BTP-eC9^[19], and those with outer branched chains, such as L8-BO^[13], have gained favor among researchers due to their excellent photovoltaic performance. Nevertheless, their performance for as-cast devices remains confined by constrained blend morphology and limited crystallinity without any modification, resulting in the PCE of 15%-16% (Figure 3a and Table S6).
由于非富勒烯受体 （NFA） 有机太阳能电池 （OSC） 具有卓越的光电特性、重量轻、机械柔韧性、半透明性和可扩展性，科学界和商业界都对非富勒烯受体 （NFA） 有机太阳能电池 （OSC） 的开发进行了广泛的研究。^[1-4] Y6 NFA ^[5] 出现后，研究人员致力于从 BZIC 的结构衍生而来的 A-DA'D-A 型的里程碑^[6]为了实现单结 OSC 接近 20% 的功率转换效率 （PCE），我们付出了相当大的努力来了解分子特性、自组装结构、材料工程和器件物理学之间的相关性。^{[7][8][9][10][11][12][[13][14]} 然而，这些器件需要精细的器件修改，例如热退火、溶剂退火或增材制造工程。^[2] 尽管在这些微妙的调节方法之后已经实现了光伏性能的显着改进，但共混纳米形态仍处于亚热力学状态，这可能会影响器件在储存过程中的稳定性。因此，没有任何前/后处理的铸态设备是 OSC 真正商业化的要求。^[15-16]然而，阻碍铸态 OSC 性能的关键挑战仍然存在，特别是对于与激子动力学相关的 NFA。 目前，NFA 的结构可以通过使用强缺电子核心单元、独特的熔融环骨架和各种侧链的调制来优化。在典型的 Y 系列 NFA 中，连接到噻吩[3,2-b]噻吩核心β位置的外侧链被认为在微调内禀分子构象、结晶度和光伏性能方面起着至关重要的作用。 具有外部线性链的 Y 系列 NFA，如 N3^[17]、BTP-4Cl^[18]、BTP-eC9^[19]，以及具有外部支链的 NFA，如 L8-BO[¹³]^] 因其出色的光伏性能而受到研究人员的青睐。 然而，它们在铸态器件中的性能仍然受到受限的共混形态和有限的结晶度的限制，没有任何修饰，导致 PCE 为 15%-16%（图 3a 和表 S6）。

Aiming to address this critical issue, we have chosen to employ the alkylthio chain strategy, which is a practical and commonly used method in the design of efficient polymer electron donor materials (such as PDBTFBZS^[20], PBDTT-S-TT^[21], PPsDF2FBT^[22], J61^[23], PBN-S^[24], and PBDTSF-FBT^[25]) and NFA materials (such as IEICS-4F^[26], IDTS-4F^[27], MS1^[28], and BTPS-4F^[29]) to regulate energy levels, modify intermolecular interaction, and enhance charge mobility. The sulfur (S) atom possesses an empty 3d orbital, which allows it to manipulate molecular symmetry, solubility, polarity, and absorbance. These manipulations ultimately result in differences in film formation properties, charge mobility, and photovoltaic performance of devices.^[30] It is important to note that the strategies reported previously mainly focused on addressing the crystallinity of the corresponding molecules. However, the solubility remains limited due to the strong intermolecular interactions, which poses a challenge for achieving better solubility in as-cast devices. although the use of extended branch chains shows promise in improving solubility, it significantly restricts absorption capabilities (absorption range, extinction coefficient) and molecular packing, which crucially affects the light-harvesting ability and carrier transport capability. Therefore, it is imperative to explore a novel alkylthio chain strategy to establish a trade-off between crystallinity and solubility for efficient as-cast OSCs.
为了解决这一关键问题，我们选择采用烷基硫代链策略，这是设计高效聚合物电子供体材料（如 PDBTFBZS^[20]、PBDTT-S-TT^[21]、PPsDF2FBT^[22]、J61）的一种实用且常用的方法^[23]、PBN-S^[24] 和 PBDTSF-FBT^[25]）和 NFA 材料（如 IEICS-4F^[26]、IDTS-4F^[27]、MS1^[28] 和 BTPS-4F^[29]） 调节能级、改变分子间相互作用并增强电荷迁移率。硫 （S） 原子具有空的 3d 轨道，这使它能够操纵分子对称性、溶解度、极性和吸光度。这些操作最终导致器件的成膜特性、电荷迁移率和光伏性能的差异。^[30]值得注意的是，之前报道的策略主要集中在解决相应分子的结晶度上。 然而，由于强烈的分子间相互作用，溶解度仍然有限，这为在 as-cast 器件中实现更好的溶解度带来了挑战。尽管使用延长支链在提高溶解度方面显示出前景，但它显着限制了吸收能力（吸收范围、消光系数）和分子包装，这对光捕获能力和载流子运输能力产生了关键影响。因此，当务之急是探索一种新的烷基硫代链策略，以建立高效铸态 OSC 的结晶度和溶解度之间的权衡。

Figure 1. The chemical structures of NFAs decorated with alkylthio chains in (a) our work and (b) previous other groups' work
图 1.（a） 我们的工作和 （b） 以前其他小组的工作中用烷基硫代链修饰的 NFA 的化学结构.

In this study, we investigated the utilization of uniquely outer branched 3,7-dimethyl-octylthio chains for the construction of a novel NFA molecule named BTP-S-DMO (Figure 1a). Additionally, we developed a highly efficient palladium-catalyzed synthesis method for the short multi-branched alkylthio chains (SMBA), resulting in a readily available and high-yield NFA. For comparison, we also synthesized a long linear alkylthio-modified NFA referred to as BTP-S-C12. Using these BTP-S-series NFAs, we conducted a comprehensive investigation to systematically examine the significant effects of alkylthio chains on both molecular packing and micromorphology.
在这项研究中，我们研究了独特的外支链 3,7-二甲基-辛硫基链在构建名为 BTP-S-DMO 的新型 NFA 分子中的利用（图 1a）。此外，我们开发了一种高效的钯催化合成方法，用于短多支链烷基硫代链 （SMBA），从而产生一种容易获得且高产率的 NFA。为了进行比较，我们还合成了一种长线性烷基硫代修饰的 NFA，称为 BTP-S-C12。使用这些 BTP-S 系列 NFA，我们进行了一项全面的研究，以系统地检查烷基硫代链对分子堆积和微形态的显着影响。

Modifying the configuration of alkylthio chains results in significant variation in the solubility, crystallinity, light-harvesting, and stacking behavior of these NFAs, leading to changes in their charge-transporting properties and photovoltaic performance. These findings are supported by the analysis techniques of single-crystal X-ray diffraction pattern (SC-XRD), two-dimensional grazing incidence wide-angle X-ray scattering (2D-GIWAXS), atomic force microscopy (AFM), temperature-dependent photoluminescence (TD-PL) analyses, and in situ spectroscopy. Furthermore, it is deduced that employing BTP-S-DMO with the SMBA strategy results in a narrow bandgap and favorable three-dimensional charge transport networks. The ordered and tight π-π stacking, diminished trap-state density, and attenuated energy disorder facilitate the conversion process from photons to electrons. Consequently, the optimized as-cast binary OSCs based on D18:BTP-S-DMO achieved a record-breaking PCE of 18.4% with a V_oc of 0.85 V, a J_sc of 27.3 mA cm^-2, and an FF of 79.1%, surpassing the previously reported values for as-cast devices. The results illustrate the feasibility of adopting this SMBA strategy for high-performance as-cast OSCs and present a new direction for enhancing morphology manipulation and photovoltaic improvements in NFAs.
修饰烷基硫代链的构型会导致这些 NFA 的溶解度、结晶度、光捕获和堆叠行为发生显著变化，从而导致其电荷传输特性和光伏性能发生变化。这些发现得到了单晶 X 射线衍射图 （SC-XRD）、二维掠入射广角 X 射线散射 （2D-GIWAXS）、原子力显微镜 （AFM）、温度依赖性光致发光 （TD-PL） 分析和原位光谱分析技术的支持。此外，推断将 BTP-S-DMO 与 SMBA 策略结合使用会产生窄带隙和有利的三维电荷传输网络。有序和紧密的 π-π 堆叠、陷阱态密度降低和衰减的能量无序促进了从光子到电子的转换过程。因此， 基于 D18：BTP-S-DMO 的优化铸态二进制 OSC 实现了创纪录的 18.4% 的 PCE，V _oc 为 0.85 V，J _sc 为 27.3 mA ^cm-2，FF 为 79.1%，超过了之前报道的铸态值设备。结果说明了将这种 SMBA 策略用于高性能铸态OSC 的可行性，并为增强 NFA 的形态操作和光伏改进提出了新的方向。

Scheme 1. (a) Traditional synthetic routes of TT-SR. (b) Our designed synthetic route of TT-SR by palladium-catalyzing coupling reaction. (c) The synthetic route of two NFAs.
方案 1.（a） TT-SR 的传统合成路线。（b） 我们设计的钯催化偶联反应合成 TT-SR 路线。（c） 两种 NFA 的合成路线。

2. Results and discussion
2. 结果和讨论

2.1. Material Synthesis and Characterization
2.1. 材料合成和表征

Two new types of BTP-S-series NFAs with branched or linear alkylthio chains attached to the fused-ring core were synthesized through the palladium-catalyzed synthesis method, resulting in higher yields compared to the traditional methodology.^{[29, 31-32]} The target NFAs were identified as BTP-S-DMO and BTP-S-C12, according to the different alkylthio chains. The successful synthetic route of two NFAs is presented in Scheme 1 and the detailed procedures are described in the Supporting Information (SI). Compound 1 was synthesized by following previously reported literature.^[5] Compounds 2(a-b) were obtained via two steps of bromination and thiolation reactions. Key intermediates 3(a-b) were synthesized through an efficient palladium-catalyzed coupling reaction between compound 1 and compounds 2(a-b), with a yield of over 90%, which differs from the previously reported processes. Subsequently, compounds 3(a-b) were subjected to NBS, triisopropylchlorosilane, and tributyl tin chloride to synthesize compounds 6(a-b) in high yield. Double-coupling intermediate products, compounds 7(a-b), were prepared via a Stille coupling reaction of compounds 6(a-b) and 4,7-dibromo-5,6-dinitrobenzo[c][1,2,5]thiadiazole. Fused-ring cores, compounds 9(a-b), were obtained in three steps via Cadogan ring-closing reaction, alkylation, and deprotecting reaction from compounds 7(a-b). Corresponding dialdehydes, compounds 10(a-b), were synthesized via the Vilsmeier reaction of compounds 9(a-b) with DMF/POCl₃. Finally, the two-fold Knoevenagel condensation reaction between the dialdehydes 10(a-b) and 2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene) malononitrile (2FIC) yielded the BTP-S-DMO and BTP-S-C12 as dark blue solids in 85~90% isolated yield. the molecular structures of NFAs and intermediates were identified by nuclear magnetic resonance (NMR) and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) (Figure S1-32).
通过钯催化合成方法合成了具有支链或线性烷基硫基链连接到熔环核的新型 BTP-S 系列 NFA，与传统方法相比，产率更高。^{[29， 31-32]} 根据不同的烷基硫基链，将目标 NFA 鉴定为 BTP-S-DMO 和 BTP-S-C12。方案 1 中介绍了两种 NFA 的成功合成路线 ，支持信息 （SI） 中描述了详细过程。化合物 1 是通过以下先前报道的文献合成的。^[5] 化合物 2（a-b） 是通过溴化和硫醇化反应两步获得的。化合物 1 和化合物 2（a-b） 之间通过高效的钯催化偶联反应合成了关键中间体 3（a-b），产率超过 90%，这与以前报道的工艺不同。随后，化合物 3（a-b） 经 NBS、三异丙基氯硅烷和三丁基氯化锡合成化合物 6（a-b） in 高产率。通过化合物 6（a-b） 和 4,7-二溴-5,6-二硝基苯并[c][1,2,5]噻二唑的 Stille 偶联反应制备双偶联中间产物化合物 7（a-b）。 熔融环核，化合物 9（a-b），通过卡多根闭环反应、烷基化和化合物 7（a-b） 的脱保护反应分三步获得。相应的二醛，化合物 10（a-b），通过化合物 9（a-b） 与 DMF/POCl₃ 的 Vilsmeier 反应合成。最后，二醛 10（a-b） 和 2-（5,6-二氟-3-氧代-2,3-二氢-1H-inden-1-ylidene）丙二腈 （2FIC） 之间的双倍 Knoevenagel 缩合反应得到 BTP-S-DMO 和 BTP-S-C12 为深蓝色固体，分离产率为 85~90%。通过核磁共振 （NMR） 和基质辅助激光解吸/电离飞行时间质谱 （MALDI-TOF MS） （图 S1-32）。

Single crystallography provides a comprehensive understanding of the chemical structure of NFAs. Despite unsuccessful attempts to grow the single crystal of BTP-S-C12, a high-quality single crystal of BTP-S-DMO was obtained by slowly diffusing methanol solution into a chloroform solution of BTP-S-DMO. Figure 2a illustrates the single-crystal structure of BTP-S-DMO, and the crystal parameters can be found in Table S1. BTP-S-DMO (CDCC number 2291164) exhibits an inverted banana-curved molecular geometry caused by the intramolecular non-covalent bond interactions between the electron-withdrawing terminal groups and electron-donating cores, resulting in an S^…O interlock distance of 2.76 Å. The dihedral angle between the end-group and the π-core of BTP-S-DMO is significantly smaller (4.26° and 1.64°), compared to that of Y6 (22.7°).^[33] Although the molecular skeleton displays good planarity due to the strong intramolecular S/O conformational locks, the two bulky 3,7-dimethyl-octylthio chains on the fused-ring projecting outward from the core extend in opposite directions. Analyzing the single-crystal structure yields insights into the molecular configuration and solid packing behavior. The BTP-S-DMO dimers exhibit partial overlap between the π-core unit of one molecule and the end-group of adjacent molecules, resulting in a short π-π interaction at a distance of 3.42 Å (Figure 2b and 2c). The π-π stacking between adjacent BTP-S-DMO molecules is attributed to non-covalent interactions, including π/π and F/S interactions. Therefore, the BTP-S-DMO crystal incorporates diverse non-covalent interactions that likely contribute significantly to its intermolecular stacking, resulting in a three-dimensional (3D) network for charge transport (Figure 2d). Consequently, BTP-S-DMO shows the 3D network packing structure with a maximum framework, with L_x = 15.899 Å along the major axis and L_y = 10.979 Å along the minor axis, owing to its minimal intermolecular interactions. Therefore, we discovered that the presence of outer short multi-branched alkylthio chains on the fused-ring core can optimize charge transfer, leading to enhanced efficiency. These findings demonstrate that different linear/branched alkylthio chains at the fused-ring core significantly affect the molecular planarity, packing, and aggregation states. Such influence should not be overlooked.
单晶学提供了对 NFA 化学结构的全面了解。尽管生长 BTP-S-C12 单晶的尝试未成功，但通过将甲醇溶液缓慢扩散到 BTP-S-DMO 的氯仿溶液中，获得了高质量的 BTP-S-DMO 单晶。图 2a 说明了 BTP-S-DMO 的单晶结构，晶体参数见表 S1。BTP-S-DMO（CDCC 编号 2291164）表现出倒香蕉弯曲的分子几何形状，这是由吸电子末端基团和供电子核心之间的分子内非共价键相互作用引起的，导致 S^...O 联锁距离为 2.76 Å。与 Y6 （22.7°） 相比，BTP-S-DMO 的端基与 π 核之间的二面角明显更小（4.26° 和 1.64°）。^[33] 尽管由于强大的分子内 S/O 构象锁，分子骨架显示出良好的平面性，但熔合环上从核心向外突出的两条笨重的 3,7-二甲基辛硫基链以相反的方向延伸。分析单晶结构可以深入了解分子构型和固体堆积行为。BTP-S-DMO 二聚体在一个分子的 π 核单元和相邻分子的末端基之间表现出部分重叠，导致在 3.42 Å 的距离处产生短暂的 π-π 相互作用（图 2b 和 2c）。相邻 BTP-S-DMO 分子之间的 π-π 堆叠归因于非共价相互作用，包括 π/π 和 F/S 相互作用。 在此之前，BTP-S-DMO 晶体结合了多种非共价相互作用，这些相互作用可能对其分子间堆叠有重大贡献，从而形成用于电荷传输的三维 （3D） 网络（图 2d）。 因此，BTP-S-DMO 显示了具有最大框架的 3D 网络堆积结构，由于其分子间相互作用最小，沿长轴的 L_x = 15.899 Å，沿短轴的 L_y = 10.979 Å。因此，我们发现熔环磁芯上存在外部短多支链烷基硫代链可以优化电荷转移，从而提高效率。这些发现表明，熔环核心处不同的线性/支链烷基硫代链显着影响分子平面性、堆积和聚集状态。这种影响不容忽视。

Figure 2. (a) Single-crystal structure of BTP-S-DMO. The π-π interaction of BTP-S-DMO for (b) top view and (c) side view (the alkyl chains and hydrogen atoms are omitted for clarity). (d) Single-crystal packing diagrams from the top view of BTP-S-DMO.
图 2.（a） BTP-S-DMO 的单晶结构。BTP-S-DMO 在 （b） 顶视图和 （c） 侧视图下的 π-π 相互作用（为清楚起见，省略了烷基链和氢原子）。（d） BTP-S-DMO 俯视图的单晶封装图。

The two NFAs (BTP-S-C12 and BTP-S-DMO), which have similar structures, exhibited a gradual increase in solubility in chloroform. Short multi-branched alkylthio chains displayed properties that are as effective in improving solubility in small molecules as long-branched chains. This deduction is made based on the observed increase in solubility of BTP-S-C12 and BTP-S-DMO in chloroform. Thermogravimetric analysis (TGA) showed that the two NFAs have good thermostability, with decomposition occurring at around 314~318℃ under N₂ atmosphere. In addition, the TGA data indicated that the length of branched and linear alkylthio chains has minimal influence on the thermostability of these NFAs as shown in Figure S33.
具有相似结构的两种 NFA （BTP-S-C12 和 BTP-S-DMO） 在氯仿中的溶解度逐渐增加。短的多支链烷基硫代链在提高小分子溶解度方面表现出与长支链一样有效的特性。该推论是根据观察到的 BTP-S-C12 和 BTP-S-DMO 在氯仿中的溶解度增加而得出的。T气密分析表明，两种 NFA 具有良好的热稳定性，在 N ₂ 气氛下，在 314~318°C 左右发生分解。此外，TGA 数据表明，支链和线性烷基硫代 chains 的长度对这些 NFA 的热稳定性影响最小，如图 S33 所示。

2.2 Optical and Electrochemical Properties
2.2 光学和电化学性质

Figure 3. (a) Plots of PCE versus Jsc of the reported as-cast OSCs. Normalized UV-Vis absorption spectra of two NFAs in (b) chloroform solutions and (c) thin films. (d) Molecular energy levels of D18, BTP-S-DMO, and BTP-S-C12.
图 3.（a） PCE 与 Jsc 的报道的铸模 OSC 的图。 两种 NFA 在 （b） 氯仿溶液和 （c） 薄膜中的归一化紫外-可见吸收光谱。（d） D18、BTP-S-DMO 和 BTP-S-C12 的分子能量水平。

Table 1. Optical, electrochemical properties of D18, two NFAs, and Y6
表 1.D18 两种 NFA 和 Y6 的光学、电化学特性

In Figures 3a and 3b, the normalized UV-Vis absorption spectra of BTP-S-DMO and BTP-S-C12 are presented for both chloroform solution (1×10^-5 M) and thin film state. The corresponding data are collected in Table 1. In dilute chloroform solutions, all BTP-S-series NFAs share the same backbone and ending groups, resulting in almost identical absorption spectra within the range of 400~800 nm. These spectra exhibit a maximum absorption peak ($$) at 726 nm. When spin-coated to form thin films, both BTP-S-DMO and BTP-S-C12 NFAs exhibit a noticeable bathochromic absorption shift of approximately 106~112 nm. Moreover, the spectra reveal prominent vibration shoulder peaks, indicating the presence of strong electronic coupling and intermolecular interactions in the solid state.^[34] The optical bandgaps ($$) of BTP-S-DMO and BTP-S-C12 were determined from their thin-film absorption onset ($$) of 923 and 927 nm, respectively, corresponding to 1.34 eV for both materials. Notably, the absorption range of the films for both NFAs (650~1000 nm) complements that of D18 (400~650 nm), which can be advantageous for solar energy harvesting. Compared to Y6^[5] and Y6-BO^[38], BTP-S-DMO exhibits broader spectra, enabling the achievement of a high short-circuit current density (J_SC) in the resulting photovoltaic devices.
$$ $$ $$ 在图 3a 和 3b 中，显示了 BTP-S-DMO 和 BTP-S-C12 在氯仿溶液 （1×1 ^0-5 M） 和薄膜状态下的归一化紫外-可见吸收光谱。表 1 中收集了相应的数据。在稀氯仿溶液中，所有 BTP-S 系列 NFA 共享相同的主链和末端基团，从而在 400~800 nm 范围内产生几乎相同的吸收光谱。这些光谱在 726 nm 处显示出最大吸收峰 （）。当旋涂形成薄膜时，BTP-S-DMO 和 BTP-S-C12 NFA 都表现出大约 106~112 nm 的明显浴变色吸收偏移。此外，光谱揭示了突出的振动肩峰，表明固态中存在强电子耦合和分子间相互作用。^[34] BTP-S-DMO 和 BTP-S-C12 的 光学带隙 （） 分别由它们的 923 和927 nm 的薄膜吸收起始 （） 确定，对应于两种材料的 1.34 eV。值得注意的是，两种 NFA 薄膜的吸收范围 （650~1000 nm） 与 D18 的吸收范围 （400~650 nm） 互补，这有利于太阳能收集。 与 Y6^[5] 和 Y6-BO^[38] 相比，BTP-S-DMO 表现出更宽的光谱，从而能够在所得光伏器件中实现高短路电流密度 （J_SC）。

The changes in bandgaps are attributable to the variations in energy levels induced by the diverse alkylthio chains. It is crucial to analyze the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). Using the cyclic voltammetry (CV) technique, these energy levels were calculated and resulted in the values of -5.49/-4.02 eV, -5.51/-4.00 eV, and -5.45/-3.53 eV for BTP-S-DMO, BTP-S-C12, and D18, respectively (shown in Figure 3c and Figure S34). The analysis suggests a cascade energy structure exists between the two NFAs and the donor molecule D18 that favors charge transport.
带隙的变化归因于不同烷基硫代链诱导的能级变化。分析最高占据分子轨道 （HOMO） 和最低未占据分子轨道 （LUMO） 的能级至关重要。使用循环伏安法 （CV） 技术计算这些能级，得出 BTP-S-DMO、BTP-S-C12 和 D18 的值分别为 -5.49/-4.02 eV、-5.51/-4.00 eV 和 -5.45/-3.53 eV（如图 3c 和图S 34 所示）分析表明，两个 NFA 和供体分子 D18 之间存在级联能量结构，有利于电荷传输。

2.3 Theoretical Calculation
2.3 理论计算

Figure 4. The optimized (a) top-view and (b) side-view conformations of two NFAs. (c) The dielectric constant of BTP-S-DMO and BTP-S-C12 as a function of frequency.
图 4.两个 NFA 的优化 （a） 俯视图和 （b） 侧视图构象。 （c） BTP-S-DMO 和 BTP-S-C12 的介电常数随频率的变化。

To investigate the impact of linear and branched alkylthio chains on the molecular geometries and frontier molecular orbitals of these NFAs, density functional theory (DFT) calculations were performed using the Gaussian package B3LYP/6-31G(d,p) system.^[39] In Figure 4a-b and Figure S36, the optimal molecular geometries, molecular orbital distributions, and electronic static potential (ESP) distributions of BTP-S-DMO and BTP-S-C12 are displayed using Multiwfn. Both NFAs exhibit a quasi-coplanar geometry. However, the overall flatness of the molecular skeleton of NFAs is influenced by different types of linear and branched chains. The dihedral angles between the central core and electron-accepting end groups in BTP-S-DMO (2.7° and 6.8°) are notably smaller than those in BTP-S-C12 (5.7° and 14.1°). The dissociation of exciton in organic absorbers depends not only on the driving force at the donor/acceptor (D/A) interface but also on the binding energy of the excitons themselves. Specifically, the binding energy of excitons in organic semiconductors decreases as the dielectric constant of surroundings increases. Therefore, measuring the dielectric constant (ɛ_r) as a function of frequency can provide insights into the strength of exciton binding in different materials. The ɛ_r values of BTP-S-C12 and BTP-S-DMO are 3.15 and 3.35, respectively (Figure 4c). The increase in ɛ_r from BTP-S-C12 to BTP-S-DMO could be attributed to higher packing orientation and density, which correlates well with the stronger intermolecular interaction of BTP-S-DMO. This enhanced ɛ_r promotes improved charge transport, thereby enabling BTP-S-DMO-based devices to achieve higher J_sc and FF. These effects will be further discussed in detail below.
为了研究线性和支链烷基硫代链对这些 NFA 的分子几何形状和前沿分子轨道的影响，使用高斯包 B3LYP/6-31G（d，p） 系统进行了密度泛函理论 （DFT） 计算。^[39] 在图 4a-b 和图 S36 中，BTP-S-DMO 和 BTP-S-C12 的最佳分子几何形状、分子轨道分布和电子静电势 （ESP） 分布使用 Multiwfn 显示。两种 NFA 都表现出准共面几何结构。然而，NFA 分子骨架的整体平坦度受不同类型的线性链和支链的影响。 BTP-S-DMO 中中心核心和电子接受端基之间的二面角 s（2.7° 和 6.8°）明显小于 BTP-S-C12 中的二面角s（5.7° 和 14.1°）。有机吸收剂中激子的解离不仅取决于供体/受体 （D/A） 界面处的驱动力，还取决于激子本身的结合能。具体来说，有机半导体中激子的结合能随着周围环境介电常数的增加而降低。因此，测量介电常数 （ɛ_r） 与频率的函数关系可以深入了解不同材料中激子结合的强度。 BTP-S-C12 和 BTP-S-DMO 的 ɛ r 值分别为 3.15 和 3.35（图 4c）。 从 BTP-S-C12 到 BTP-S-DMO 的 ɛ r 增加可归因于更高的堆积取向和密度，这与 BTP-S-DMO 更强的分子间相互作用密切相关。这种增强的 ɛ_r 促进了电荷传输的改善，从而使基于 BTP-S-DMO 的器件能够实现更高的 J_{sc 和} FF。这些影响将在下面进一步详细讨论。

2.4 Film Formation Dynamics
2.4 成膜动力学

Figure 5. Time-dependent contour maps of in situ UV-vis absorption spectra of (a) BTP-S-C12 and (b) BTP-S-DMO neat films. (c) Time evolution of peak location and intensity of acceptors. (c) The aggregation rate of BTP-S-C12 and BTP-S-DMO blend films during spin coating.
图 5. （a） BTP-S-C12 和 （b） BTP-S-DMO 整齐薄膜的原位紫外-可见吸收光谱的时间依赖性等值线图。（c） 受体峰位置和强度的时间演变。（c） BTP-S-C12 和 BTP-S-DMO 共混膜在旋涂过程中的聚集速率。

The distinct molecular property undoubtedly has a profound impact on the film formation process. Therefore, cutting-edge in situ UV-vis absorption spectroscopy was employed to precisely monitor and analyze the dynamics of aggregation and domain size throughout the film formation period, in order to comprehensively examine the influence of the SMBA strategy on the kinetics of film formation and the distinct nanomorphology. Contour maps of the blend films with different NFAs during the film-forming process are shown in Figures 5a and 5b, while Figure 5c illustrates the time evolution of peak positions of BTP-S-DMO and BTP-S-C12. Three stages (1. Solvent evaporation, 2. Nucleation, 3 Aggregates growth) were observed from the solution to film state during the spin-coating process. As depicted in Figure 5c, we observed a longer liquid-solid transition time in the BTP-S-DMO case, which can be attributed to the higher solubility of BTP-S-DMO in chloroform solvent. This extended phase transition time is advantageous for re-self-assembly to the favorable molecular packing conditions, thereby facilitating better crystallinity in the BTP-S-DMO blend film. Additionally, Figure 5d demonstrates that the stronger miscibility between BTP-S-DMOs mitigates the assembly speed (2.79 ms^-1), ultimately promoting ordered molecular packing in the blend. On the other hand, BTP-S-C12 exhibited a higher aggregate rate, leading to a coarse morphology with excessive phase separation (discussed in the morphology section).
独特的分子特性无疑对成膜过程产生了深远的影响。因此，采用尖端的原位紫外-可见吸收光谱来精确监测和分析整个成膜过程中聚集和畴大小的动力学，以全面研究 SMBA 策略对成膜动力学和独特纳米形态的影响。图 5 a 和 5b 显示了成膜过程中具有不同 NFA 的混合薄膜的等值线图 ，而图 5c 说明了 BTP-S-DMO 和 BTP-S-C 12 峰位置的时间演变。三个阶段 （1.溶剂蒸发，2.成核，3 聚集体生长）在旋涂过程中从溶液到薄膜状态观察到。如图 5c 所示，我们在 BTP-S-DMO 情况下观察到更长的液固转变时间，这可能是由于 BTP-S-DMO 在氯仿溶剂中的溶解度较高。这种延长的相变时间有利于重新自组装到有利的分子堆积条件，从而促进 BTP-S-DMO 共混膜中更好的结晶度。此外，图 5d 表明 BTP-S-DMO 之间较强的混溶性降低了组装速度 （2.79 ^ms-1），最终促进了混合物中的有序分子堆积。另一方面，BTP-S-C12 表现出更高的聚集速率，导致形态粗糙且相位分离过度（在形态学部分讨论）。

2.5 Photovoltaic Performances
2.5 光伏性能

Figure 6. (a) Device structure diagram of these OSCs. (b) J-V curves of two groups of optimal OSCs. (c) EQE curves. Photoluminescence quenching spectra of neat NFA and blend films excited at 780 nm of (d) BTP-S-DMO and (e) BTP-S-C12. (f) J_ph vs. V_eff curves
图 6.（a） 这些 OSC 的器件结构图。（b） 两组最佳 OSCs 的 J-V 曲线。（c） EQE 曲线。（d） BTP-S-DMO 和 （e） BTP-S-C12 在 780 nm 处激发的纯 NFA 和混合薄膜的光致发光猝灭光谱。（f） Jph 与 Veff 曲线.

Table 2. Photovoltaic parameters of optimized OSCs based on donor materials D18
表 2. 基于供体材料 D18 的优化 OSC 的光伏参数

To investigate the impact of introducing diverse branched/linear alkylthio chains into the BTP-S-series NFAs on photovoltaic performance, we fabricated as-cast binary OSCs. The device structure adopted for this purpose is as follows: ITO glass/PEDOT:PSS (hole-transporting layer)/D18:NFA (active layer)/PNDIT-F3N-Br (electron-transporting layer)/Ag (Figures 6a). The photovoltaic properties of OSC devices were measured under 100 mW cm^-2 AM 1.5G simulated solar illumination in a nitrogen-filled glovebox. The D:A ratio for optimized active layers was set at 1:1.5. All the optimizing processes have been recorded in Tables S2-4 in the SI. Figures 6b-c and Table 2 depict the current-density-voltage (J-V) curves, the corresponding external quantum efficiency (EQE) spectra, and the photovoltaic parameters of optimized devices. The as-cast devices based on BTP-S-C12 with long linear shape alkylthio chains achieved a PCE of 17.0% with a V_oc of 0.85 V, a J_sc of 26.7 mA cm^-2, and an FF of 74.9%. Surprisingly, substituting the long linear chains with short muti-branched alkylthio chains in the BTP-S-DMO-based devices resulted in a significant increase in PCE, reaching a maximum value of 18.4%, with a V_oc of 0.85 V, a J_sc of 27.3 mA cm^-2, and an FF of 79.1%. This represents one of the highest values observed in as-cast OSC devices. Furthermore, the as-cast devices based on D18:BTP-S-DMO demonstrated superior photostability compared to the D18:BTP-S-C12-based devices (Figure S37). Over 120 h of light soaking, the BTP-S-DMO-based device maintained 87% of its initial PCE, while the BTP-S-C12 counterpart dropped to 54% under the same conditions. This indicates that BTP-S-DMO not only delivers a higher PCE but also exhibits a superior ability to suppress the current decay compared to BTP-S-C12. The findings of this study highlight the significant impact of alkylthio chain configuration of the fused-ring core in influencing the photovoltaic performance of OSCs.
为了研究在 BTP-S 系列 NFA 中引入多种支链/线性烷基硫代链对光伏性能的影响，我们制备了铸态二元 OSC，为此目的采用的器件结构如下：ITO玻璃/PEDOT：PSS（空穴传输层）/D18：NFA（有源层）/PNDIT-F3N-Br （电子传输层）/Ag （图 6a）。在充满氮气的手套箱中，在 100 mW ^cm-2 AM 1.5G 模拟太阳照明下测量 OSC 器件的光伏性能。优化活动图层的 D：A 比率设置为 1：1.5。所有优化过程都记录在 SI 的表 S2-4 中。 图 6b-c 和表 2 描述了电流-密度-电压 （J-V） 曲线、相应的外部量子效率 （EQE） 光谱以及优化器件的光伏参数。 基于 BTP-S-C12 的铸态器件具有长线性烷基硫代链，在 V_oc 为 0.85 V、J_sc 为 26.7 mA cm-2 和 FF 时实现了 17.0% 的 PCE，为 26.7 mA ^cm-2，FF 为 74.9%。令人惊讶的是，在基于 BTP-S-DMO 的器件中，用短多支链烷基硫代链代替长线性链导致 PCE 显着增加，达到最大值 18。4%，V_oc 为 0.85 V，J _sc 为 27.3 mA ^cm-2，FF 为 79.1%。这表示在 as-cast OSC 设备中观察到的最高值之一。此外，与基于 D18：BTP-S-C12 的器件相比，基于 D18：BTP-S-DMO 的铸态器件表现出优异的光稳定性（图S 37）。在 120 小时的光浸泡中，基于 BTP-S-DMO 的装置保持了其初始 PCE 的 87%，而 BTP-S-C12 对应物在相同条件下下降到 54%。这表明 BTP-S-DMO 不仅提供更高的 PCE，而且与 BTP-S-C12 相比，还表现出卓越的抑制电流衰减的能力。本研究的结果强调了 熔融环磁芯的烷基硫代链构型对影响 OSC 光伏性能的重大影响 。

The enhanced J_sc of BTP-S-DMO-based devices compared to BTP-S-C12-based devices is evident from their high EQE curves, as depicted in Figure 6c. The spectral response ranges of NFA-based devices progressively shift towards longer wavelengths from BTP-S-DMO to BTP-S-C12, aligning with the pattern of their absorption profiles in blend films. All as-cast devices exhibited an EQE of over 75% within the 450 nm to 850 nm range, with a maximum value of approximately 88%, suggesting efficient collection of photons. Therefore, the integrated current density (J_cal) obtained from the EQE curve for the D18:BTP-S-DMO-based device (26.5 mA cm^-2) showcases reliability in photovoltaic performance measurements, with fluctuations within 5%, as compared to D18:BTP-S-C12-based devices (26.0 mA cm^-2). These findings suggest that optimizing the configuration of the alkylthio chains can enhance the separation of photogenerated carriers, improve conversion efficiency, and consequently contribute to an improved J_sc and overall PCEs. The SMBA strategy employed in NFAs can effectively balance the V_OC, and improve the J_SC and FF, thereby enhancing the photovoltaic performance of corresponding OSCs
与基于 BTP-S-C12 的器件相比，基于 Jscof BTP-S-DMO 的增强型器件从其高 EQE 曲线中可以明显看出，如图 6c 所示。基于 NFA 的器件的光谱响应范围逐渐向从 BTP-S-DMO 到 BTP-S-C12 的更长波长移动，这与它们在混合薄膜中的吸收曲线模式一致。所有铸态器件在 450 nm 至 850 nm 范围内均表现出超过 75% 的 EQE，最大值约为 88%，表明光子的有效收集。因此，与基于 D18：BTP-S-C12 的器件 （26.0 mA cm-2） 相比，基于 D18：BTP-S-C12 的器件 （26.0 mA cm-2） 从 EQE 曲线获得的积分电流密度 （Jcal） 显示了光伏性能测量的可靠性，波动在 5% 以内。这些发现表明，优化烷基硫代链的构型可以增强光生载流子的分离，提高转化效率，从而有助于改善 Jsc 和整体 PCE。NFA 中采用的 SMBA 策略可以有效平衡 VOC，提高 JSC 和 FF，从而提高相应 OSC 的光伏性能.

2.6. Charge Dynamics
2.6. 电荷动力学

Photoluminescence (PL) measurements were performed to investigate the kinetics of exciton dissociation in the blend films. Figures 6d and 6e illustrate the strong fluorescence observed in all neat NFA films when excited at 780 nm within the 800-1200 nm range. However, BTP-S-C12 displays a relatively narrow fluorescence spectrum, which may be attributed to the less-steric central core that induces significant self-quenching. Blending with D18, all blend films effectively reduce emissions, resulting in quenching efficiencies of 99.6% and 99.2% for the BTP-S-DMO blend film and BTP-S-C12 blend film, respectively. The efficient quenching observed in BTP-S-DMO blend film indicates that the charge transfer processes between the donor and acceptor are more effective, potentially leading to an increase in J_SC
进行光致发光 （PL） 测量以研究共混物中激子解离的动力学。 图 6d 和 6 e 显示了在 800-1200 nm 范围内在 780 nm 激发时在所有纯 NFA 薄膜中观察到的强荧光。然而，BTP-S-C12 显示出相对狭窄的荧光光谱，这可能归因于诱导显着自淬灭的不太空间位位的中心核心。与 D18 共混，所有共混膜均有效减少排放，使 BTP-S-DMO 共混膜和 BTP-S-C12 共混膜的淬火效率分别为 99.6% 和 99.2%。在 BTP-S-DMO 混合膜中观察到的高效淬火表明，供体和受体之间的电荷转移过程更加有效，可能导致 J_SC 的增加.

The study aimed to investigate the behavior of exciton dissociation in OSC devices through the characterization of the relationship between the saturated photocurrent density (J_ph) and effective voltage (V_eff).^[40] Under the short-circuit conditions, the exciton dissociation efficiencies (P_diss =J_ph/V_eff) were calculated for both BTP-S-DMO and BTP-S-C12-based devices, yielding values of 97.9.0% and 96.5%, respectively, as illustrated in Figure 6f. The results indicate that the BTP-S-DMO-based devices exhibit slightly higher P_diss values compared to the BTP-S-C12-based devices, suggesting more effective processes of exciton dissociation and charge collection in the former. These factors account for the higher J_SC and FF observed in the BTP-S-DMO-based devices.
该研究旨在通过表征饱和光电流密度 （J_ph） 和有效电压 （V_eff） 之间的关系来研究 OSC 器件中激子解离的行为。^[40] 在短路条件下，计算了基于 BTP-S-DMO 和 BTP-S-C12 的器件的激子解离效率 （P_diss=J_ph/V_eff），分别产生 97.9.0% 和 96.5% 的值，如图所示图 6f.结果表明，与基于 BTP-S-C12 的器件相比，基于 BTP-S-DMO 的器件表现出略高的 P_diss 值，表明前者具有更有效的激子解离和电荷收集过程。这些因素解释了 在基于 BTP-S-DMO 的设备中观察到的较高 J_SC 和 FF。

Figure 7. (b) TPC and (c) TPV measurement of the optimized OSCs. (d) Histogram of the hole and electron mobilities of the optimized devices. Built-in potentials of the optimized OSCs were measured following the Mott-Schottky method for (e) BTP-S-DMO blend film and (f) BTP-S-C12 blend film.
图 7.（b） 优化 OSC 的 TPC 和 （c） TPV 测量。（d） 优化器件的空穴和电子迁移率的直方图。 按照 Mott-Schottky 方法测量 （e） BTP-S-DMO 混合膜和 （f） BTP-S-C12 混合膜的优化 OSC 的内置电位。

The charge recombination behaviors of these OSCs were evaluated by studying the relationship between J_sc/V_oc and incident light intensity (P_light). Under different P_light values, the corresponding J_sc follows the equation J_sc ∝(P_light)^α, where α is close to one, indicating weak bimolecular recombination of the charge carriers in the materials.^[41] Figure S39a demonstrates that the recombination parameters α for the devices based on BTP-S-DMO and BTP-S-C12 were both 0.99, suggesting negligible bimolecular recombination. Additionally, the relationship between V_oc and P_light can be described as V_oc ∝(nk_BT/q) ln(P_light), where k_B is the Boltzmann constant, T is the Kelvin temperature, and q is the elemental charge. When the slope (S) approaches 1 k_BT/q, it theoretically indicates negligible trap-assisted recombination. As shown in Figure S39b, the S values for the devices based on BTP-S-DMO and BTP-S-C12 are 1.18 k_BT/q and 1.26 k_BT/q, respectively. The lower S value for the BTP-S-DMO-based devices suggests ameliorated trap-assisted recombination potential, which is advantageous for improving their FF and PCE.
通过研究 J_sc/V_oc 与入射光强度 （P_光） 之间的关系 来评估 OSCs 的电荷复合行为。 在不同 P_光值下，相应的 J_sc 遵循方程 J_sc ∝（P_light）^α其中 α 接近 1，表明材料中电荷载流子的双分子复合较弱。^[41]图 S39a 表明，基于 BTP-S-DMO 和 BTP-S-C12 的器件的复合参数α均为 0.99，表明双分子复合可以忽略不计此外，V _oc 和 P_光之间的关系可以是描述为 V_oc ∝（nk_BT/q） ln（P_light），其中 k_B 是玻尔兹曼常数，T 是开尔文温度，q 是元素电荷。 当斜率 （S） 接近 1 k_BT/q 时，它 t理论上表示陷阱辅助复合可以忽略不计。如图 S39b 所示， 基于 BTP-S-DMO 和 BTP-S-C12 的器件的 S 值分别为 1.18 k_BT/q 和 1.26 k_BT/q。 基于 BTP-S-DMO 的装置的较低 S 值表明陷阱辅助复合电位得到改善，这有利于改善其 FF 和 PCE。

Experiments were performed to investigate the charge extraction and carrier lifetime of these devices using transient photocurrent (TPC) measurements under short-circuit conditions and transient photovoltage (TPV) measurements under open-circuit conditions. As presented in Figure 7a, the TPC curves were fitted to derive the charge extraction times for BTP-S-DMO and BTP-S-C12-based devices, which were found to be 0.31 μs and 0.39 μs, respectively. Additionally, the charge carrier lifetimes were determined from the TPV decay dynamics, which were 9.5 μs and 5.0 μs for BTP-S-DMO and BTP-S-C12-based OSCs, respectively as depicted in Figure 7b. The results indicate that the BTP-S-DMO-based devices exhibited a shorter charge extraction time and a longer charge carrier lifetime, implying higher charge mobility and weaker charge recombination in the active layers that align with their superior device performances.
进行了实验，以研究这些器件的电荷提取和载流子寿命，使用短路条件下的电流 （TPC） 测量和开路条件下的瞬态光电压 （TPV） 测量。如图 7a 所示，拟合 TPC 曲线以得出基于 BTP-S-DMO 和 BTP-S-C12 的器件的电荷提取时间，发现分别为 0.31 μs 和 0.39 μs。此外，电荷载流子寿命由 TPV 衰减动力学确定，基于 BTP-S-DMO 和 BTP-S-C12 的 OSC 分别为 9.5 μs 和 5.0 μs，如图 7b 所示。结果表明，基于 BTP-S-DMO 的器件表现出更短的电荷提取时间和更长的电荷载流子寿命，这意味着有源层中具有更高的电荷迁移率和较弱的电荷复合，这与它们的卓越器件性能相一致。

To elucidate the reasons why BTP-S-DMO-based devices exhibit suppressed charge recombination and high FF values compared to other devices, we measured the hole mobilities (μ_h) and electron mobilities (μ_e) of the two NFA layers blended with D18 using the space charge limited current (SCLC) method. The resulting μ_h values for the BTP-S-DMO and BTP-S-C12 blend films were calculated as 4.9×10^-4 and 4.3×10^-4 cm² V^-1 s^-1, respectively, as shown in Figure 7c and Figure S40. Meanwhile, the calculated value of μ_e for BTP-S-DMO-based devices was improved to 4.7×10^-4 cm² V^-1 s^-1 compared to that of BTP-S-C12-based devices (2.8×10^-4 cm² V^-1 s^-1). The enhanced values of both μ_h and μ_e can be attributed to the order and compact molecular packing of the blend film in BTP-S-DMO-based devices, which aligns well with the discussion on single-crystal data and GIWAXS results presented below. The more balanced μ_h/μ_e ratio of BTP-S-DMO-based devices (1.04) is advantageous in suppressing interfacial charge accumulation and charge recombination, consequently leading to higher FF in the resulting devices.
为了阐明与其他器件相比基于 BTP-S-DMO 的器件表现出抑制电荷复合和高 FF 值的原因，我们使用空间电荷限制电流 （SCLC） 方法测量了与 D18 混合的两个 NFA 层的空穴迁移率 （μ_h） 和电子迁移率 （μ_e）。 BTP-S-DMO 和 BTP-S-C12 混合膜的 μ h 值分别计算为 4.9×1 ^0-4 和 4.3×1 ^0-4 cm^{2 V-1 s-1}，如图 7c 和图 S 所示40. 同时，与基于 BTP-S-C12 的设备 （2.8×1 ^0-4 cm² V-1 相比，基于 BTP-S-DMO 的设备μ_e 的计算值提高到 4.7×1 ^0-4 cm^{2 V-1 s-1 s-1}）。μ_h 和 μ_e 的增强值可归因于基于 BTP-S-DMO 的器件中混合膜的顺序和紧凑的分子堆积，这与下面介绍的关于单晶数据和 GIWAXS 结果的讨论非常一致。 基于 BTP-S-DMO 的器件 μ h/μ e 比 （1.04） 更平衡，有利于抑制界面电荷积累和电荷复合，从而导致所得器件中的更高 FF。

Moreover, we characterized the trap-state densities (N_trap) for the BTP-S-C12 and BTP-S-DMO by analyzing the capacitance frequency spectra using the Walter model.^[43] The density of state (DOS) measurements yield the following representation: , where N_t represents total trap density, E_t means the center of the density of state (DOS), and δ denotes the disorder parameter. As summarized in Figures 7d and 7e, the trap density shows a decreasing trend following the sidechain modification. Notably, the trap densities are reduced from 1.16×10¹⁵ cm^-3 in D18:BTP-S-C12-based devices to 1.07×10¹⁵ cm^-3 in D18:BTP-S-DMO-based devices. The reduction in the trap density indicates a decrease in defects and suppression resulting from the short multi-branched alkylthio chain modification.^[35] It is evident that the blend films based on the SMBA strategy provide efficient pathways between neighboring NFAs, facilitating high and balanced charge transport. This characteristic is essential for further improving the performance of OSCs.
此外，我们通过使用 Walter 模型分析电容频谱来表征 BTP-S-C12 和 BTP-S-DMO 的 trap-state 密度 （N_陷阱）。 ^[43] 状态密度 （DOS） 测量产生以下表示： 其中 N_t 表示 tal 陷阱密度，E_t 表示状态密度 （DOS） 的中心，δ表示无序参数。如图 7d 和 7e 所示，陷阱密度在侧链修改后呈下降趋势。值得注意的是，陷阱密度从基于 D18：BTP-S-C12 的器件中的 1.16×^{10 15 cm-3} 降低到基于 D18：BTP-S-DMO 的器件 中的 1.07×10 15 cm-3.捕集密度的降低表明短多支链烷基硫代链修饰导致的缺陷和抑制减少。^[35]很明显，基于 SMBA 策略的混合薄膜在相邻的 NFA 之间提供了有效的途径，促进了高平衡的电荷传输。这一特性对于进一步提高 OSC 的性能至关重要。

2.8. Morphology Analysis
2.8. 形态分析

To explore the impact of branched and linear alkylthio chains on the miscibility between two NFAs and D18, droplet contact angle experiments were measured, shown in Figure S41 and Table S4. The surface tensions (γ) of D18, BTP-S-DMO, and BTP-S-C12 were estimated to be 38.7, 39.2, and 37.0 mN m^-1, respectively. Consequently, the Flory-Huggins interaction parameters (χ) between D18 and these NFAs were calculated as 0.016 κ and 0.019 κ for D18:BTP-S-DMO and D18:BTP-S-C12, respectively, using the equation of . These results were obtained by defining of χ as the Flory-Huggins interaction parameter.^[44] These results indicated excellent miscibility between D18 and BTP-S-DMO. From a thermodynamics perspective, decreased miscibility between two materials increases phase separation of the blend film at equilibrium. This result suggests that the original miscibility between D18 and BTP-S-C12 is inferior, resulting in an over-aggregated morphology in the blend film as observed in the discussed AFM images. These results prove that the SMBA of NFAs significantly impacts their miscibility with donors, providing an opportunity to control the morphologies of the resulting blend films.
为了探讨 支链和线性烷基硫代链对两种 NFA 和 D18 之间混溶性的影响，测量了液滴接触角实验，如图 S 41 和表 S4 所示。 D18、BTP-S-DMO 和 BTP-S-C12 的表面张力 （γ） 估计分别为 38.7、39.2 和 37.0 ^{mN m-1}。因此，D18 和这些 NFA 之间的 Flory-Huggins 相互作用参数 （χ） 分别计算为 D18：BTP-S-DMO 和 D18：BTP-S-C12 的 0.016 κ 和 0.019 κ，使用方程 将这些结果定义为 χ 作为 Flory-Huggins 相互作用参数获得。^[44]这些结果表明 D18 和 BTP-S-DMO 之间具有出色的混溶性。 从热力学的角度来看，两种材料之间的混溶性降低增加了平衡时混合膜的相分离。这一结果表明，D18 和 BTP-S-C12 之间的原始混溶性较差，导致混合膜中的形态过度聚集，如在讨论的 AFM 图像中观察到的那样。这些结果证明，NFA 的 SMBA 显着影响它们与供体的混溶性，为控制所得混合膜的形态提供了机会。

AFM was utilized to examine the relationship among molecular design, active layer morphology, and photovoltaic performance based on D18:NFA blend films. Both BTP-S-DMO and BTP-S-C12-based blend films display uniform and smooth surfaces, with small root-mean-square roughnesses (R_q) of 0.91 nm and 1.17 nm, respectively (Figure S42). The relatively rough morphology of the D18:BTP-S-C12 blend film adversely affected efficient exciton diffusion and greatly increased the charge recombination, resulting in lower J_SC and FF values in BTP-S-C12-based devices during the photovoltaic measurement.
AFM 用于检查基于 D18：NFA 混合薄膜的分子设计、活性层形态和光伏性能之间的关系。基于 BTP-S-DMO 和 BTP-S-C12 的混合薄膜都显示出均匀和光滑的表面，均方根粗糙度 （R_q） 分别为 0.91 nm 和 1.17 nm（图 S42）。D18：BTP-S-C12 共混膜相对粗糙的形貌对有效的激子扩散产生了不利影响，并大大增加了电荷复合，导致 基于 BTP-S-C12 的器件在光伏测量过程中的 J_SC 和 FF 值较低。

Figure 8. 2D GIWAXS patterns of (a)-(b) blend films and (c)-(d) neat films. The corresponding 1D line-cut profiles of (e) blend films and (f) neat films.
图8. （a）-（b） 混合薄膜和 （c）-（d） 纯薄膜的 2D GIWAXS 图案。（e） 混合薄膜和 （f） 纯薄膜的相应 1D 线切割曲线。

The molecular crystallinity, orientation, and packing properties of neat/blend films were further investigated using GIWAXS characterizations.
使用 GIWAXS 表征进一步研究了纯/共混薄膜的分子结晶度、取向和堆积特性。^[45-46] The 2D GIWAXS patterns and the corresponding 1D line-cut profiles in the out-of-plane (OOP) and in-plane (IP) directions are displayed in
2D GIWAXS 模型和相应的面外 （OOP） 和面内 （IP） 方向的 1D 线切割轮廓以Figure 8
图 8. The neat films exhibited a predominant
.整洁的电影表现出占主导地位“face-on” orientation, as evidenced by the strong (010) π
“正面”取向，如斯特朗 （010） π-π sta
斯塔cking diffraction peaks in the
cking 的衍射峰OOP direction. To calculate the crystal coherence length (CCLs), the following formula was employed: CCL = 1.8
OOP 方向。为了计算晶体相干长度 （CCL），采用以下公式：CCL = 1.8π/FWHM, where FWHM represents the full width at half-maximum of peaks in the intensity profile.
/FWHM，其中 FWHM 表示强度分布中峰半峰处的全宽。^[47] Comparatively, BTP-S-DMO neat film had larger CCLs of 19.3 nm than that of BTP-S-C12 neat film (13.2 nm). A gradual increase in CCLs was observed from BTP-S-C12 neat film to BTP-S-DMO neat film, while the
相比之下，BTP-S-DMO 纯膜的 CCL 比 BTP-S-C12 纯膜 （13.2 nm） 大，为 19.3 nm。从 BTP-S-C12 纯膜到 BTP-S-DMO 纯膜，CCLs 逐渐增加，而π-π stacking distances
π 堆叠距离 decreased
减少from 3.53
从 3.53 起Å to 3.45
至 3.45Å. The
.这se
硒 results indicate a more ordered stacking arrangement in the BTP-S-DMO neat film, which aligns well with the findings of the single crystal analysis. The blend films
结果表明 BTP-S-DMO 整齐薄膜中的堆叠排列更加有序，这与单晶分析的结果非常吻合。混合薄膜 showed strong (010) peaks in the
在OOP direction, implying a preferential face-on orientation, facilitating efficient charge transport in the vertical direction across the electrodes.
OOP 方向，意味着优先的正面方向，有助于在垂直方向上跨电极的高效电荷传输。With increasing in solubility and crystallinity from BTP-S-C12 to BTP-S-
随着溶解度和结晶度的增加，从 BTP-S-C12 增加到 BTP-S-DMO,
DMO、the stronger
更强π-π stacking diffraction peak of D18:BTP-S-DMO blend film was located at
D18：BTP-S-DMO 共混膜的堆叠衍射峰位于q_z = 1.75 Å^-1, which correspond to the d-spacings of
，它们对应于3.58 Å than that of
比D18:BTP-S-C12 blend film
D18：BTP-S-C12 共混膜nd (
ND （3.591 Å). The tighter π-π stacking and larger CCL in the OOP direction of the
).在 OOP 方向上，π π 堆叠更紧密，CCL 更大D18:BTP-S-DMO
D18：BTP-S-DMO blend film indicate that the short muti-branched chain on the fused-ring core lead to stronger crystallinity and more ordered molecular packing, facilitating charge transport and suppress
混合膜表明熔融环核上的短多支链导致更强的结晶度和更有序的分子堆积，有利于电荷传输和抑制ing
正在 charge recombination, which is consistent with the data from AFM images. The charge mobilities of the two NFA blend films obtained from the SCLC method discussed are highly correlated with the GIWAXS results presented herein. Thus, the high FF (79.1%) and ideal morphology observed in the
电荷复合，这与 AFM 图像中的数据一致。从讨论的 SCLC 方法获得的两种 NFA 混合膜的电荷迁移率与本文提供的 GIWAXS 结果高度相关。因此，在D18:BTP-S-DMO
D18：BTP-S-DMO-based devices can be attributed to the synergistic effects of well-ordered stacking, the balanced
基于器件的器件可以归因于有序堆叠的协同效应，即平衡的μ_e/μ_h ratio, and limited trap-assisted charge recombination. The favorable phase separation of the
比率和有限的陷阱辅助电荷复合。有利的相分离D18:BTP-S-DMO
D18：BTP-S-DMO blend film enhances efficient exciton dissociation and charge transport, leading to high
混合膜增强了高效的激子解离和电荷传输，从而实现高J_SC and FF in the resulting devices
和 FF. These findings suggest that
.这些发现表明the SMBA strategy
SMBA 策略effectively fine-tunes the morphology of blend film, making it advantageous.
有效地微调混合膜的形态，使其具有优势。

3. Conclusions
3. 结论

In summary, a new family of BTP-S-series NFAs was designed and synthesized through efficient palladium-catalyzed coupling, with alkylthio chains substituted at the outer positions of the fused-ring core. Specifically, 3,7-dimethyloctylthio and dodecylthio were used as substituents. The incorporation of these short multi-branched alkylthio chains had significant effects on the optoelectronic properties, molecular stacking, morphology, and photovoltaic parameters of the resulting OSCs. An improved PCE of up to 18.4% was observed in the as-cast OSCs based on D18:BTP-S-DMO, accompanied by a V_OC of 0.85 V, a J_SC of 27.3 mA cm^-2, an FF of 79.1%. This achievement corresponds to the highest reported PCE among as-cast OSCs. The exceptional performance of BTP-S-DMO-based device can be attributed to several factors, including minimal changes in UV-Vis absorption, reduced π-π stacking distance, and an ordered/tightened 3D charge transport network. These factors facilitate effective exciton dissociation, balanced charge mobility, alleviated biomolecular recombination, and diminished trap-state density. Our study highlights the critical role of alkylthio chain engineering in precisely adjusting the molecular configuration and solid-state properties in NFAs. Furthermore, this study will encourage further investigation of the SMBA strategy for the development of new semiconductor materials in organic electronics.
总之，通过高效的钯催化偶联设计和合成了一个新的 BTP-S 系列 NFA 系列，烷基硫代链在熔融环磁芯的外部位置被取代。具体来说，3,7-二甲基辛硫代和十二烷基硫代用作取代基。这些短的多支链烷基硫代链的掺入对所得 OSC 的光电特性、分子堆叠、形态和光伏参数有显着影响。在基于 D18：BTP-S-DMO 的铸态 OSC 中观察到 PCE 改善高达 18.4%，伴有 0.85 V 的 V OC，27.3 mA ^cm-2 的 J_SC，FF 为 79.1%。这一成就对应于铸模 OSC 中报告的最高 PCE。基于 BTP-S-DMO 的器件的卓越性能可归因于几个因素，包括 UV-Vis 吸收的最小变化、缩短的 π-π 堆叠距离以及有序/收紧的 3D 电荷传输网络。这些因素有助于有效的激子解离、平衡电荷迁移率、减轻生物分子重组和降低陷阱态密度。我们的研究强调了烷基硫代链工程在精确调整 NFA 中的分子构型和固态特性方面的关键作用。此外，本研究将鼓励进一步研究 SMBA 策略，以开发有机电子中的新半导体材料。

[1] Y. Liu, B. Li, C.-Q. Ma, F. Huang, G. Feng, H. Chen, J. Hou, L. Yan, Q. Wei, Q. Luo, Q. Bao, W. Ma, W. Liu, W. Li, X. Wan, X. Hu, Y. Han, Y. Li, Y. Zhou, Y. Zou, Y. Chen, Y. Li, Y. Chen, Z. Tang, Z. Hu, Z.-G. Zhang, Z. Bo, Sci. China Chem. 2022, 65, 224.
[1]Y. Liu， B. Li， C.-Q.马， 黄峰， 冯国， 陈浩， 侯建军， 闫立， 魏琦， 罗琦， 包桂， 马伟， 刘伟， 李伟， 万， 胡， 韩宇， 李宇， 周宇， 邹宇， 陈宇， 李宇， 陈宇， 唐志强， 胡志强Zhang， Z. Bo， 中国化学2022， 65， 224.

[2] G. Zhang, F. R. Lin, F. Qi, T. Heumüller, A. Distler, H.-J. Egelhaaf, N. Li, P. C. Y. Chow, C. J. Brabec, A. K. Y. Jen, H.-L. Yip, Chemical Reviews 2022, 122, 14180.
[2]G. Zhang， F. R. Lin， F. Qi， T. Heumüller， A. Distler， H.-J.Egelhaaf， N. Li， P. C. Y. Chow， CJ Brabec， AKY Jen， H.-L.叶， 化学评论2022， 122， 14180.

[3] Z. Luo, T. Xu, C. e. Zhang, C. Yang, Energy & Environmental Science 2023, DOI: 10.1039/D3EE00908D.
[3]Z. Luo， T. Xu， C. E. Zhang， C. Yang， 能源与环境科学2023， DOI： 10.1039/D3EE00908D.

[4] H. Tang, Y. Bai, H. Zhao, X. Qin, Z. Hu, C. Zhou, F. Huang, Y. Cao, Advanced Materials 2023, DOI: https://doi.org/10.1002/adma.2022122362212236.
[4]H. Tang， Y. Bai， H. Zhao， X. Qin， Z. 胡， C. 周， F. Huang， Y. Cao， Advanced Materials2023， DOI： https://doi.org/10.1002/adma.2022122362212236.

[5] J. Yuan, Y. Zhang, L. Zhou, G. Zhang, H.-L. Yip, T.-K. Lau, X. Lu, C. Zhu, H. Peng, P. A. Johnson, M. Leclerc, Y. Cao, J. Ulanski, Y. Li, Y. Zou, Joule 2019, 3, 1140.
[5]袁建军， 张彦， 周， 张国强， H.-L.叶 T.-K.Lau， X. Lu， C. Zhu， H. Peng， PA Johnson， M. Leclerc， Y. Cao， J. Ulanski， Y. Li， Y. Zou， 焦耳2019， 3， 1140.

[6] L. Feng, J. Yuan, Z. Zhang, H. Peng, Z.-G. Zhang, S. Xu, Y. Liu, Y. Li, Y. Zou, ACS Applied Materials & Interfaces 2017, 9, 31985.
[6]L. Feng， J. Yuan， Z. Zhang， H. Peng， Z.-G.Zhang， S. Xu， Y. Liu， Y. Li， Y. Zou， ACS Applied Materials & Interfaces2017， 9， 31985.

[7] L. Zhu, M. Zhang, J. Xu, C. Li, J. Yan, G. Zhou, W. Zhong, T. Hao, J. Song, X. Xue, Z. Zhou, R. Zeng, H. Zhu, C.-C. Chen, R. C. I. MacKenzie, Y. Zou, J. Nelson, Y. Zhang, Y. Sun, F. Liu, Nature Materials 2022, 21, 656.
[7]朱玲， 张明， 徐建， 李建， 严建， 周建， 钟伟， 郝涛， 宋建军， 薛旭， 周志强， 曾荣， 朱浩， C.-C.Chen， R. C. I. MacKenzie， Y. Zou， J. Nelson， Y. Zhang， Y. Sun， F. Liu， Nature Materials2022， 21， 656.

[8] Z. Zheng, J. Wang, P. Bi, J. Ren, Y. Wang, Y. Yang, X. Liu, S. Zhang, J. Hou, Joule 2022, 6, 171.
[8]郑志强， 王建军， 毕鹏， 任建， 王宇， 杨宇， 刘晓军， 张建军， 侯建军， 焦耳2022， 6， 171.

[9] Y. Wei, Z. Chen, G. Lu, N. Yu, C. Li, J. Gao, X. Gu, X. Hao, G. Lu, Z. Tang, J. Zhang, Z. Wei, X. Zhang, H. Huang, Advanced Materials 2022, 34, 2204718.
[9]魏彦彦， 陈志强， 卢国军， 于恺， 李建军， 高建军， 顾旭， 浩旭， 陆建军， 唐振军， 张志伟， 张旭， 黄浩， 先进材料2022， 34， 2204718.

[10] W. Gao, F. Qi, Z. Peng, F. R. Lin, K. Jiang, C. Zhong, W. Kaminsky, Z. Guan, C.-S. Lee, T. J. Marks, H. Ade, A. K.-Y. Jen, Advanced Materials 2022, 34, 2202089.
[10]W. Gao， F. Qi， Z. Peng， F. R. Lin， K. 江， 钟振， W. Kaminsky， Z. Guan， C.-S.李，TJ 马克斯，H. Ade，AKYJen， 先进材料2022， 34， 2202089.

[11] K. Chong, X. Xu, H. Meng, J. Xue, L. Yu, W. Ma, Q. Peng, Advanced Materials 2022, 34, 2109516.
[11]张国强， 徐旭， 孟海， 薛俊， 余丽， W. 马， 彭倩， 先进材料2022， 34， 2109516.

[12] Y. Li, Y. Guo, Z. Chen, L. Zhan, L. Zuo, C. He, Z. Bi, N. Yao, S. Li, G. Zhou, Y. Yi, Y. M. Yang, H. Zhu, W. Ma, F. Gao, F. Zhang, H. Chen, Energy & Environmental Science 2022, 15, 855.
[12]李彦， 郭彦， 陈志骊， 詹立， 左立， 何志， 毕志妍， 姚南， 李孳， 周冠， 易彦， 杨玉明， 朱浩， 马伟， 高飞， 张飞， 陈浩， 能源与环境科学2022， 15， 855.

[13] C. Li, J. Zhou, J. Song, J. Xu, H. Zhang, X. Zhang, J. Guo, L. Zhu, D. Wei, G. Han, J. Min, Y. Zhang, Z. Xie, Y. Yi, H. Yan, F. Gao, F. Liu, Y. Sun, Nature Energy 2021, 6, 605.
[13]李振， 周建， 宋建， 徐建， 张浩， 张旭， 郭建军， 朱立军， 魏大军， 韩建军， 张建军， 张建军， 谢志强， 易毅， 闫海， 高发， 刘建军， 孙宇， 自然能源2021， 6， 605.

[14] Q. Liu, Y. Jiang, K. Jin, J. Qin, J. Xu, W. Li, J. Xiong, J. Liu, Z. Xiao, K. Sun, S. Yang, X. Zhang, L. Ding, Science Bulletin 2020, 65, 272.
[14]刘琦， 江彦， 金国， 秦建军， 徐建军， 李伟， 熊建军， 刘建军， 肖志强， 孙国强， 杨绍军， 张晓军， 丁立军， 科学通报2020， 65， 272.

[15] R. Ma, Y. Tao, Y. Chen, T. Liu, Z. Luo, Y. Guo, Y. Xiao, J. Fang, G. Zhang, X. Li, X. Guo, Y. Yi, M. Zhang, X. Lu, Y. Li, H. Yan, Sci. China Chem. 2021, 64, 581.
[15]马锐， 陶彦， 陈彦， 刘涛， 罗志强， 郭彦， 肖彦， 方建， 张刚， 李晓明， 郭晓明， 张晓明， 卢晓明， 李彦， 闫浩， 中国化学.2021， 64， 581.

[16] D. Li, H. Lu, Y.-N. Chen, X. Ma, H. Zhang, H. Wang, X. Yu, X. Xu, Z. Zhang, X. Xu, Y. Liu, Z. Ma, A. Zhang, Z. Bo, Chemistry of Materials 2022, 34, 8840.
[16]D. Li， H. Lu， Y.-N.陈晓马， 张海， 王海， 余晓， 徐旭， 张志强， 徐旭， 刘玉， 马志强， 张亚， 波志强， 材料化学2022， 34， 8840.

[17] K. Jiang, Q. Wei, J. Y. L. Lai, Z. Peng, H. K. Kim, J. Yuan, L. Ye, H. Ade, Y. Zou, H. Yan, Joule 2019, 3, 3020.
[17]江国， 魏启， 赖玉良， 彭志强， 金浩强， 袁俊杰， 叶丽光， 阿德， 邹宇， 邹浩骏， 焦耳2019， 3， 3020.

[18] Y. Cui, H. Yao, L. Hong, T. Zhang, Y. Tang, B. Lin, K. Xian, B. Gao, C. An, P. Bi, W. Ma, J. Hou, National Science Review 2020, 7, 1239.
[18]崔彦， 姚海， 洪立， 张涛， 唐彦， 林斌， 娴国安， 高斌， 安振， 毕平， 马伟， 侯建军， 国家科学评论2020， 7， 1239.

[19] Y. Cui, H. Yao, J. Zhang, K. Xian, T. Zhang, L. Hong, Y. Wang, Y. Xu, K. Ma, C. An, C. He, Z. Wei, F. Gao, J. Hou, Advanced Materials 2020, 32, 1908205.
[19]崔彦， 姚海， 张建， 娴国， 张涛， 洪立， 王彦， 徐宇， 马， 安， 何建军， 魏志强， 高飞， 侯建军， 先进材料2020， 32， 1908205.

[20] K. Li, Z. Li, K. Feng, X. Xu, L. Wang, Q. Peng, Journal of the American Chemical Society 2013, 135, 13549.
[20]李国、李振、国丰、徐旭、王立、彭倩，美国化学会杂志2013， 135， 13549.

[21] C. Cui, W.-Y. Wong, Y. Li, Energy & Environmental Science 2014, 7, 2276.
[21]C. Cui， W.-Y.Wong， Y. Li， 能源与环境科学2014， 7， 2276.

[22] M. A. Uddin, T. H. Lee, S. Xu, S. Y. Park, T. Kim, S. Song, T. L. Nguyen, S.-j. Ko, S. Hwang, J. Y. Kim, H. Y. Woo, Chemistry of Materials 2015, 27, 5997.
[22]M. A. Uddin， T. H. Lee， S. Xu， S. Y. Park， T. Kim， S. Song， T. L. Nguyen， S.-j. Ko， S. Hwang， J. Y. Kim， H. Y. Woo， 材料化学2015， 27， 5997.

[23] H. Bin, Z.-G. Zhang, L. Gao, S. Chen, L. Zhong, L. Xue, C. Yang, Y. Li, Journal of the American Chemical Society 2016, 138, 4657.
[23]H. Bin， Z.-G.Zhang， L. Gao， S. Chen， L. Zhong， L. Xue， C. Yang， Y. Li， 美国化学会杂志2016， 138， 4657.

[24] Y. Wu, H. Yang, Y. Zou, Y. Dong, J. Yuan, C. Cui, Y. Li, Energy & Environmental Science 2019, 12, 675.
[24]Y. Wu， H. Yang， Y. Zou， Y. Dong， J. Yuan， C. Cui， Y. Li， 能源与环境科学2019， 12， 675.

[25] G. Zhang, X. Xu, Z. Bi, W. Ma, D. Tang, Y. Li, Q. Peng, Advanced Functional Materials 2018, 28, 1706404.
[25]张国， 徐旭， 毕志强， W. 马， 唐大， 李宇， 彭启， 先进功能材料2018， 28， 1706404.

[26] S. Chen, H. Yao, B. Hu, G. Zhang, L. Arunagiri, L.-K. Ma, J. Huang, J. Zhang, Z. Zhu, F. Bai, W. Ma, H. Yan, Advanced Energy Materials 2018, 8, 1800529.
[26]陈淑娴， 姚海， 胡斌， 张国， L. Arunagiri， L.-K.马， J. Huang， J. Zhang， Z. Zhu， F. Bai， W. 马， H. Yan， 先进能源材料2018， 8， 1800529.

[27] A. Zeng, M. Pan, B. Lin, T.-K. Lau, M. Qin, K. Li, W. Ma, X. Lu, C. Zhan, H. Yan, Solar RRL 2019, 4, 1900353.
[27]A. Zeng， M. Pan， B. Lin， T.-K.Lau， M. Qin， K. Li， W. 马， X. Lu， C. Zhan， H. Yan， 太阳能RRL2019， 4， 1900353.

[28] W. Zheng, Y. Ma, Q. Tu, Z. Li, D. Cai, J.-Y. Wang, C. Tang, Q. Zheng, Chem. Eng. J. 2022, 427, 131022.
[28]郑伟文， 马彦， 涂启骏， 李志强， 蔡大军， J.-Y.Wang， C. Tang， Q. Zheng， 化学工程学博士2022， 427， 131022.

[29] A. M. H. Cheung, H. Yu, S. Luo, Z. Wang, Z. Qi, W. Zhou, L. Arunagiri, Y. Chang, H. Yao, H. Ade, H. Yan, Journal of Materials Chemistry A 2020, 8, 23239.
[29]张安海， 俞海禅， 罗淑娴， Z. Wang， Z. Qi， W. 周， L. Arunagiri， Y. Chang， H. Yao， H. Ade， H. Yan， 材料化学学报A2020， 8， 23239.

[30] H. Yang, C. Cui, Y. Li, Accounts of Materials Research 2021, 2, 986.
[30]H. Yang， C. Cui， Y. Li， 材料研究账户2021， 2， 986.

[31] J. A. Schneider, A. Dadvand, W. Wen, D. F. Perepichka, Macromolecules 2013, 46, 9231.
[31]J. A. Schneider， A. Dadvand， W. 温， D. F. Perepichka， 大分子2013， 46， 9231.

[32] R. Kong, Z. Xiao, F. Xie, J. Jiang, L. Ding, New Journal of Chemistry 2017, 41, 2895.
[32]R. Kong， Z. Xiao， F. Xie， J. 江， L. Ding， 新化学杂志2017， 41， 2895.

[33] L. Zhu, M. Zhang, G. Zhou, T. Hao, J. Xu, J. Wang, C. Qiu, N. Prine, J. Ali, W. Feng, X. Gu, Z. Ma, Z. Tang, H. Zhu, L. Ying, Y. Zhang, F. Liu, Advanced Energy Materials 2020, 10, 1904234.
[33]朱立军， 张明， 周， 郝涛， 徐建， 王建， 邱建军， N. Prine， 阿里， 冯伟文， 顾旭， 马， 唐振东， 朱浩， 英立英， 张宇， 刘飞， 先进能源材料2020， 10， 1904234.

[34] G. Li, X. Zhang, L. O. Jones, J. M. Alzola, S. Mukherjee, L.-w. Feng, W. Zhu, C. L. Stern, W. Huang, J. Yu, V. K. Sangwan, D. M. DeLongchamp, K. L. Kohlstedt, M. R. Wasielewski, M. C. Hersam, G. C. Schatz, A. Facchetti, T. J. Marks, Journal of the American Chemical Society 2021, 143, 6123.
[34]G. Li， X. Zhang， L. O. Jones， JM Alzola， S. Mukherjee， L.-w. Feng， W. Zhu， CL Stern， W. Huang， J. Yu， VK Sangwan， DM DeLongchamp， KL Kohlstedt， MR Wasielewski， MC Hersam， GC Schatz， A. Facchetti， TJ Marks， 美国化学会杂志2021， 143， 6123.

[35] L. Ma, Y. Cui, J. Zhang, K. Xian, Z. Chen, K. Zhou, T. Zhang, W. Wang, H. Yao, S. Zhang, X. Hao, L. Ye, J. Hou, Advanced Materials 2023, 35, 2208926.
[35]L. 马， Y. Cui， J. Zhang， K. Xian， Z. Chen， K. 周， T. Zhang， W. Wang， H. Yao， S. Zhang， X. Hao， L. Ye， J. Hou， Advanced Materials2023， 35， 2208926.

[36] J. Zhou, D. He, Y. Li, F. Huang, J. Zhang, C. Zhang, Y. Yuan, Y. Lin, C. Wang, F. Zhao, Advanced Materials 2023, 35, 2207336.
[36]J. 周， D. He， Y. Li， F. Huang， J. Zhang， C. Zhang， Y. Yuan， Y. Lin， C. Wang， F. Zhao， 先进材料2023， 35， 2207336.

[37] Z. Zhang, Y. Li, G. Cai, Y. Zhang, X. Lu, Y. Lin, Journal of the American Chemical Society 2020, 142, 18741.
[37]张振仁， Y. Li， G. Cai， Y. Zhang， X. Lu， Y. Lin， 美国化学会杂志2020， 142， 18741.

[38] M. Zhang, L. Zhu, T. Hao, G. Zhou, C. Qiu, Z. Zhao, N. Hartmann, B. Xiao, Y. Zou, W. Feng, H. Zhu, M. Zhang, Y. Zhang, Y. Li, T. P. Russell, F. Liu, Advanced Materials 2021, 33, 2007177.
[38]张明， 朱立军， 郝涛， G. 周， 邱建军， 赵志强， N. Hartmann， 肖斌， 邹玉， 冯伟文， 朱浩， 张明， 张玉， 张玉， 李玉， T. P. Russell， 刘飞， 先进材料2021， 33， 2007177.

[39] Z. Zhong, X. Liu, L. Li, Z. Han, Y. He, X. Xu, J. Hai, R. Zhu, J. Yu, Sci. China Chem. 2023, 66, 242.
[39]钟振振， 刘晓晓， 李丽， 韩振仁， 何宇， 徐晓， 海建， 朱仁， 余建， 中国化学.2023， 66， 242.

[40] P. W. M. Blom, V. D. Mihailetchi, L. J. A. Koster, D. E. Markov, Advanced Materials 2007, 19, 1551.
[40]P. W. M. Blom， V. D. Mihailetchi， L. J. A. Koster， D. E. Markov， 先进材料2007， 19， 1551.

[41] A. K. K. Kyaw, D. H. Wang, V. Gupta, W. L. Leong, L. Ke, G. C. Bazan, A. J. Heeger, ACS Nano 2013, 7, 4569.
[41]AKK Kyaw， D. H. Wang， V. Gupta， W. L. Leong， L. Ke， GC Bazan， AJ Heeger， ACS Nano2013， 7， 4569.

[42] N. Su, J. Chen, M. Peng, G. Li, R. M. Pankow, D. Zheng, J. Ding, A. Facchetti, T. J. Marks, Journal of Energy Chemistry 2023, 79, 321.
[42]N. Su， J. Chen， M. Peng， G. Li， R. M. Pankow， D. Zheng， J. Ding， A. Facchetti， TJ Marks， 能源化学杂志2023， 79， 321.

[43] S. Khelifi, K. Decock, J. Lauwaert, H. Vrielinck, D. Spoltore, F. Piersimoni, J. Manca, A. Belghachi, M. Burgelman, Journal of Applied Physics 2011, 110, 094509.
[43]S. Khelifi， K. Decock， J. Lauwaert， H. Vrielinck， D. Spoltore， F. Piersimoni， J. Manca， A. Belghachi， M. Burgelman， Journal of Applied Physics2011， 110， 094509.

[44] T. Xu, Z. Luo, R. Ma, Z. Chen, T. A. Dela Peña, H. Liu, Q. Wei, M. Li, C. e. Zhang, J. Wu, X. Lu, G. Li, C. Yang, Angewandte Chemie International Edition 2023, 62, e202304127.
[44]徐天， 罗志强， 马睿， 陈志强， T. A. 德拉佩尼亚， 刘海， 魏启， 李明， 张振英， 吴建军， 卢旭， 李国强， 杨振， 应用化学国际版2023， 62， e202304127.

[45] W. Zhong, M. Zhang, G. Freychet, G. M. Su, L. Ying, F. Huang, Y. Cao, Y. Zhang, C. Wang, F. Liu, Advanced Materials 2022, 34, 2107316.
[45]钟伟文， 张明， G. Freychet， 苏建明， 英立英， 黄飞， 曹玉， 张玉， 王建军， 刘飞， 先进材料2022， 34， 2107316.

[46] A. Mahmood, J.-L. Wang, Solar RRL 2020, 4, 2000337.
[46]A. Mahmood， J.-L.王，太阳能 RRL2020,4,2000337。

[47] X. Li, F. Pan, C. Sun, M. Zhang, Z. Wang, J. Du, J. Wang, M. Xiao, L. Xue, Z.-G. Zhang, C. Zhang, F. Liu, Y. Li, Nature Communications 2019, 10, 519.
[47]X. Li， F. F. Pan， C. Sun， M. Zhang， Z. Wang， J. Du， J. Wang， M. Xiao， L. Xue， Z.-G.张俊杰， F. Liu， Y. Li， 自然通讯2019， 10， 519.