Dual Optimization of Interface Defects and Hole Transporting Layers with Tetrathiafulvalene Derivatives for Antimony Selenosulfide Solar Cells

Abstract

Modification of hole transporting layers (HTLs) to reduce the interface defects is an important strategy to promote hole extraction and suppress charge recombination for Sb2(S,Se)3 (antimony selenosulfide) solar cells. Herein, a simple doping method with the tetrathiafulvalene derivatives (MeS‐TTF and Cyano‐TTF) is developed to reduce the dangling bonding defects on the surface of Sb2(S,Se)3 films and improve the photovoltaic performances of Sb2(S,Se)3 solar cells. The studies show that the tetrathiafulvalene derivatives can effectively passivate the ionic defects through the chelation mechanism with Sb atoms and suppress the nonradiative recombination. Meanwhile, the MeS‐TTF dopant can also enhance the hole mobility of HTLs and improve the hole transport. The results indicate that the MeS‐TTF can achieve the dual function of interface defect passivation and hole mobility improvement. As a result of the dual‐function dopant, a significant increase in efficiency from 7.73% to 8.45% can be obtained. The outcomes of this study highlight that this dual‐function doping strategy is an effective method to passivate the interface defects and enhance the hole mobility for the excellent photovoltaic performances of Sb2(S,Se)3 solar cells.