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

Autor: Jianning Ding, Quan Sun, Yi Zhang, Ningyi Yuan, Xuguang Jia, Huafei Guo, Jing Zhang, Shuai Zhang, Yikai Wang
Rok vydání: 2020
Předmět:
Zdroj: Science China Chemistry. 63:827-832
ISSN: 1869-1870
1674-7291
DOI: 10.1007/s11426-019-9728-7
Popis: 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 PEDOTPSS 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 PEDOTPSS. 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.
Databáze: OpenAIRE
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