Bis(4-methylthio)phenyl)amine-based hole transport materials for highly-efficient perovskite solar cells: insight into the carrier ultrafast dynamics and interfacial transport

• 作者: Huafei Guo Jianning Ding Jing Zhang Ningyi Yuan Quan Sun Shuai Zhang Xuguang Jia Yi Zhang Yikai Wang
• 来源期刊: 中国科学:化学（英文版）
• 年，卷（期）: 2020,（6）
• 页码范围: 827-832
• 页数: 6页
• 语种: 英文

摘要

Hole transport layers (HTLs) play a significant role in the performance of perovskite solar cells.A new class of linear small-molecules based on bis(4-methylthio)phenyl)amine as an end group,carbon,oxygen and sulfur as the center atoms for the center unit (denoted as MT-based small-molecule),respectively,have been applied as HTL,and two of them presented the efficiency over 20％ in the planar inverted perovskite solar cells (PSCs),which demonstrated a significant improvement in comparison with the widely used HTL,poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (known as PEDOT:PSS),in the planar inverted architecture.The ultrafast carrier dynamics show that the excited hot carrier cooling process of MT-based small-molecule HTL samples is faster than that of PEDOT:PSS samples.The kinetic analysis of photo-bleaching peaks of femtosecond transient absorption spectra reveals that the traps at the interface between MT-based small-molecule HTLs and MAPbI3 can be filled much quicker than that at PEDOT/MAPbI3 interfaces.Moreover,the hole injection time from MAPbI3 to MT-based small-molecule HTLs is around 10 times quicker than that to PEDOT:PSS.Such quick trap filling and hole extraction bring a significant enhancement in photovoltaic performances.These findings uncover the carrier transport mechanisms and illuminate a promising approach for the design of new HTLs for highly-efficient perovskite solar cells.