Benzothiadiazole-based hole transport materials for high-efficiency dopant-free perovskite solar cells: Molecular planarity effect

• 来源期刊: 能源化学
• 年，卷（期）: 2020,（5）
• 页码范围: 115-120
• 页数: 6页
• 语种: 英文

摘要

A new benzothiadiazole-based D-A-D hole transport material (DTBT) has been designed and synthesized with a more planar structure by introducing of thiophene bridges.The results indicate a lower band gap and quite higher hole mobility for the DTBT.Furthermore,the enhancement in molecular planarity with simple thiophene unit increases the hole mobility of DTBT (8.77 × 10-4 cm2 V-1 s-1) by about 40％.And when DTBT is used as hole transport material in perovskite solar cells,the photoelectric conversion efficiency of the corresponding dopant-free devices is also significantly improved compared with that of the conventional BT model molecule without thiophene.In terms of device stability,DTBT-based devices show a favorable long-term stability,which keep 83％ initial efficiency after 15 days.Therefore,the introducing of thiophene bridges in D-A-D typed HTMs can improve the molecular planarity effectively,thereby increasing the hole mobility and improving device performance.