Inspired by the encouraging properties of Ge-fused heterocyclic dithienogermole (DTG) in optoelectronic applications, we here report two narrow-bandgap acceptor–donor′–donor–donor′–acceptor (A–D′–D–D′–A)-type isomeric nonfullerene acceptors based on DTG (DTG-IW with inward-facing side chains vs DTG-OW with outward-facing side chains) for use in organic solar cells (OSCs). The introduction of the inward-facing side chains into the backbone results in extremely confined face-on crystallites in the solid state, as verified by grazing-incidence wide-angle X-ray scattering measurements. This result is attributed mainly to a better power conversion efficiency (PCE) of 9.16% in the OSC based on a blend of DTG-IW with a narrow-bandgap PTB7-Th donor polymer, as compared with the corresponding DTG-OW-based one. Furthermore, the appealing feature of the blend mixing of the narrow-bandgap donor and acceptor pair is that it enables the construction of a green-tinted efficient semitransparent OSC with a PCE of 6.19% and transmittance of 50.4% in the green wavelength region through incorporation of the recently formulated semitransparent Ag/Sb₂O₃/Ag electrode. Overall, in addition to providing useful perspectives into the side-chain engineering of nonfullerene acceptors, this work highlights that OSC based on the A–D′–D–D′–A-type DTG is a promising narrow-bandgap acceptor for further improvement of the performance of semitransparent OSCs.

中文翻译：

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基于双硫代诺莫尔的非富勒烯受体：侧链的方向和绿色色调的高效半透明有机太阳能电池的发展的作用。

受Ge稠合杂环二硫杂诺克分子（DTG）在光电应用中令人鼓舞的特性的启发，我们在此报告了两种窄带隙受体-供体'-供体-供体'-受体（A–D'–D–D'–A）-用于有机太阳能电池（OSC）的基于DTG（具有向内侧链的DTG-IW与具有向外侧链的DTG-OW）的2型异构体非富勒烯受体。向内引入的侧链进入主链会导致固态的面状微晶非常局限，这已通过掠入射广角X射线散射测量得到了证实。该结果主要归因于与相应的基于DTG-OW的DTG-IW相比，基于DTG-IW与窄带隙PTB7-Th供体聚合物的共混物在OSC中具有9.16％的更高功率转换效率（PCE）。 。此外，₂ O ₃ / Ag电极。总体而言，除了为非富勒烯受体的侧链工程提供有用的观点外，这项工作还强调基于A–D′–D–D′–A型DTG的OSC是有希望的进一步改进的窄带隙受体半透明OSC的性能。