A small molecule donor STB-4 with dithieno[2,3-d′:2′,3′-d′]benzo[1,2-b:4′,5′-b′]dithiophene (DTBDT) as the central moiety was designed and synthesized for solution-processed bulk-heterojunction solar cells. An optimized power conversion efficiency of 8.17% with an open-circuit voltage of 0.904 V, a short-circuit current of 13.33 mA cm⁻², and a fill factor FF of 0.67 was achieved after solvent annealing (SVA). According to the detailed morphology investigations, we found that SVA refined the phase-separated morphologies of the blends, allowing the domains to become well defined with anappropriate size that is beneficial for device performance.

中文翻译：

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噻吩[3,4- b ]噻吩基的小分子供体，具有π-扩展的二噻吩并苯并二噻吩核，可用于高效溶液加工的有机太阳能电池

以二噻吩并[2,3- d '：2'，3'- d ']苯并[1,2- b：4'，5'- b ']二噻吩（DTBDT）为中心的小分子供体STB-4设计并合成了用于溶液处理的本体异质结太阳能电池。在溶剂退火（SVA）之后，在0.904 V的开路电压，13.33 mA cm ^-2的短路电流和0.67的填充系数FF的情况下，实现了8.17％的最佳功率转换效率。根据详细的形态学调查，我们发现SVA改进了共混物的相分离形态，从而使域以适当的尺寸变得清晰定义，这有利于设备性能。