A weak electron-donating ladder-type heteroarene, indacenodibenzothiophene (IDBT), is designed and synthesized for the development of acceptor–donor–acceptor (A–D–A)-type small-molecule acceptors featuring a large optical bandgap to match high-performance low-bandgap electron donors. Small-molecule acceptor NIDBT based on the IDBT core and 2-(2,3-dihydro-3-oxo-1H-inden-1-ylidene)propanedinitrile as an electron-deficient end group is designed and synthesized. NIDBT shows a wide optical bandgap of 1.84 eV with a high absorption coefficient. A low-bandgap polymer PTB7-Th is selected as the donor to construct photovoltaic devices with NIDBT as the acceptor. After a thermal-annealing treatment at 160 °C for 10 min, an optimal power conversion efficiency (PCE) of 4.45% with an open-circult voltage (V_oc) of 0.831 V, a short-circuit current (J_sc) of 11.45 mA cm⁻² and a fill factor (FF) of 46.73% is realized.

中文翻译：

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利用新的茚并二苯并噻吩核用于有机太阳能电池的大带隙小分子电子受体†

设计并合成了一种弱电子给体梯型杂芳基茚达索二苯并噻吩（IDBT），用于开发受体-供体-受体（AD-A）型小分子受体，具有大的光学带隙以匹配高性能低带隙电子供体。设计并合成了基于IDBT核和2-（2,3-二氢-3-氧代-1 H-茚满-1-亚烷基）丙烷作为电子缺陷端基的小分子受体NIDBT。NIDBT显示出1.84 eV的宽光学带隙和高吸收系数。选择低带隙聚合物PTB7-Th作为供体，用NIDBT构建光伏器件作为接受者。经过160°C的热退火处理10分钟后，开环电压（V _oc）为0.831 V，短路电流（J _sc）为11.45时，最佳功率转换效率（PCE）为4.45％。实现了mA cm ^-2和46.73％的填充系数（FF）。