Influence of Hole Mobility on Charge Separation and Recombination Dynamics at Lead Halide Perovskite and Spiro-OMeTAD Interface

Autor: Maning Liu, Masaru Endo, Hanming Liu, Atsushi Wakamiya, Yasuhiro Tachibana, Pathmaperuma Arachchige S. R Padmaperuma, Ai Shimazaki
Rok vydání: 2019
Předmět:
Zdroj: Journal of Photopolymer Science and Technology. 32:727-733
ISSN: 1349-6336
0914-9244
Popis: High efficiency lead halide perovskite solar cells employ spiro-OMeTAD or PTAA as a hole transporting material. This type of hole conductor requires dopants mainly to improve hole mobility. Although such doping has improved solar cell performance, in particular open circuit photovoltage and fill factor, the mechanism of the improvement has rarely been elucidated. Here, we demonstrate influence of dopants in spiro-OMeTAD on interfacial charge separation and recombination processes for a MAPbI3 perovskite film sandwiched by an m-TiO2 film and a spiro-OMeTAD layer by employing a series of transient absorption spectroscopies. The interfacial charge recombination time was significantly retarded by the doping. We propose that the retardation of the charge recombination originates from relatively longer distance of holes from the perovskite/spiro-OMeTAD interface owing to the increased hole mobility by the doping, potentially increasing Voc of the solar cell.
Databáze: OpenAIRE