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^-4cm^2 V^-1s^-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.
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.
基金
the National Key R&D Program of China(2018YFB1500101)
National Basic Research Program of China(No.2015CB932200)
CAS-Iranian Vice Presidency for Science and Technology Joint Research Project(No.116134KYSB20160130).
