Effects of Oxygen Atoms Introduced at Different Positions of Non-Fullerene Acceptors in the Performance of Organic Solar Cells with Poly(3-hexylthiophene)

Abstract

With the development of large-area fabrication technologies for organic solar cells (OSCs), poly(3-hexylthiophene) (P3HT) is the best choice as a photovoltaic donor polymer because it can be easily synthesized in the scale of kilograms at low cost. However, non-fullerene acceptors (NFAs) matching with P3HT for high performance OSCs are very rare. Herein, by introducing oxygen atoms into the side chains or the fused-ring core of indaceno[1,2-b:5,6-b′]dithiophene, we synthesized two new A 2 −A 1 −D−A 1 −A 2 type NFAs, where benzotriazole (BTA) and 2-(1,1dicyanomethylene)rhodanine were used as the bridged A 1 and terminal A 2 , respectively. The final NFAs, named BTA43 and BTA53, show wider absorption spectra and enhanced intermolecular/intramolecular interaction in comparison with their analogue BTA3 without oxygen atoms. The photovoltaic devices based on P3HT:BTA43 and P3HT:BTA53 can achieve a high power conversion efficiency of 6.56 and 6.31%, respectively, which are obviously higher than that of BTA3 (5.64%). Our results provide a simple and effective strategy to design promising NFAs to pair with the classic photovoltaic polymer P3HT.

Photoisomerization of dicyanorhodanine-functionalized thiophenes

“…38,39 More recently, the evolving research area focusing on SM non-fullerene acceptors (NFAs) has adopted RCN, and numerous examples containing this structure have been reported. [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58] RCN-based NFAs have achieved PCEs beyond the 10% mark, [59][60][61][62][63] with some of the highest performers reaching values of 10.78%, 64 12.16%, 65 and 12.27%. 66 The RCN acceptor has also been incorporated into p-conjugated polymer donors, leading to OPV devices with PCEs of 5.30%, 67 8.13%, 68 and 9.12%.…”

Recent Advances of Film–Forming Kinetics in Organic Solar Cells

“…According to previous research, the molecular orientation of the donor and acceptor at the interface directly determines the driving forces of the built-in electric field [27]. When the orientation of the donor and acceptor is consistent, the coupling force between the donor and acceptor is large, leading to a strong built-in electric field, which is beneficial for exciton dissociation [28][29][30]. Furthermore, generated free electrons and holes need to transport to the corresponding anode and cathode through the pure acceptor and donor phases, respectively.…”

Advances in Organic Photovoltaics

“…与 IDT-2BR 相比, 其吸收红移, 结晶性增强, 性能也提升至 6.3%. 朱晓张等 [121] 将苯并噻二唑单元替换为吸电子能力更强 的酯基修饰的噻吩并 [3,4-b]噻吩, 合成了 ATT-3, 其与 P3HT 共混的器件效率为 6.26%; 周二军等 [122] 使用苯并 三氮唑作为 π 桥单元, 1,1-二氰基亚甲基-罗丹宁作为端 基, 合成了 BTA43, 其与 P3HT 共混的器件效率为 6.56%. 陈兴国等 [123] 将 π 桥改为酯基取代的噻吩稠合的 苯并三氮唑单元, 同时将端基替换为 1,1-二氰基亚甲基-罗丹宁单元, 合成了 JC2, 其与 P3HT 共混的器件效率 超过 6%.…”