We developed a novel nonfullerene electron acceptor, IffBR, that consists of electron-rich indaceno[1,2-b:5,6-b′]dithiophene as the central unit and an electron-deficient 5,6-difluorobenzo[c][1,2,5]thiadiazole unit flanked with rhodanine as the peripheral group. IffBR exhibits peak UV–vis absorbance at 658 nm, which is complementary with the absorption profiles of the wide-bandgap conjugated polymers poly[4,8-bis(4,5-dihexylthiophen-2-yl)benzo[1,2-b:4,5-b′]-dithiophene-alt-2-(2-butyloctyl)-5,6-difluoro-4,7-di(thiophen-2-yl)-2H-benzo[d][1,2,3]triazole] (PBTA-BO) and the fullerene acceptor [6,6]-phenyl-C71-butyric acid methyl ester (PC₇₁BM). The ternary device constructed with PBTA-BO/PC₇₁BM/IffBR as the light-absorption layer exhibited significantly better photovoltaic performance than those obtained from devices based on a bulk-heterojunction layer comprised of binary components. This improvement was attributed to the broadened absorbance, formation of cascade charge-transfer pathways, reduced nongeminate recombination, enhanced charge extraction, and more favorable morphologies of the bulk-heterojunction films. The optimized ternary device exhibited a power conversion efficiency of 9.06%, which is significantly higher than those of binary devices based on either PBTA-BO/IffBR (6.24%) or PBTA-BO/PC₇₁BM (4.73%). These results indicate that IffBR is an outstanding electron acceptor, suitable for the fabrication of nonfullerene or multicomponent-blend polymer solar cells.

中文翻译：

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通过掺入窄带隙非富勒烯受体增强三元聚合物太阳能电池的光伏性能

我们开发了一种新型的非富勒烯电子受体IffBR，它由富电子吲哚并[1,2- b：5,6- b ']二噻吩为中心单元和缺电子的5,6-二氟苯并[ c ] [ 1,2,5]噻二唑单元的侧翼为若丹宁。IffBR在658 nm处表现出峰值的UV-vis吸收，与宽带隙共轭聚合物聚[4,8-双（4,5-二己基噻吩-2-基）苯并[1,2- b]的吸收曲线互补：4,5- b '] -dithiophene- ALT -2-（2-丁基辛基）-5,6-二氟- 4,7-二（噻吩-2-基）-2- ħ -苯并[ d] [1,2,3]三唑]（PBTA-BO）和富勒烯受体[6,6]-苯基-C71-丁酸甲酯（PC ₇₁ BM）。用PBTA-BO / PC ₇₁ BM / IffBR作为光吸收层构成的三元器件的光伏性能要比从基于包含二元组分的体异质结层的器件获得的光电性能好得​​多。这种改善归因于宽的吸收度，级联电荷转移途径的形成，减少的非双键重组，增强的电荷提取以及体-异质结薄膜的更有利的形貌。经过优化的三元器件的功率转换效率为9.06％，远高于基于PBTA-BO / IffBR（6.24％）或PBTA-BO / PC ₇₁的二进制器件的功率转换效率。BM（4.73％）。这些结果表明，IffBR是一种出色的电子受体，适用于制造非富勒烯或多组分共混聚合物太阳能电池。