Direct Spectroscopic Observation of the Hole Polaron in Lead Halide Perovskites

被引：19

作者：

Liu, Cunming ^{[1
]}

Tsai, Hsinhan ^{[2
]}

Nie, Wanyi ^{[2
]}

Gosztola, David J. ^{[3
]}

Zhang, Xiaoyi ^{[1
]}

机构：

[1] Argonne Natl Lab, Xray Sci Div, Lemont, IL 60439 USA

[2] Los Alamos Natl Lab, Ctr Integrated Nanotechnol, Los Alamos, NM 87545 USA

[3] Argonne Natl Lab, Ctr Nanoscale Mat, Lemont, IL 60439 USA

来源：

JOURNAL OF PHYSICAL CHEMISTRY LETTERS | 2020年 / 11卷 / 15期

关键词：

X-RAY-ABSORPTION; STABILIZATION; INTENSITY; MOBILITY; CARRIERS;

D O I：

10.1021/acs.jpclett.0c01708

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The intrinsic photophysical origin of lead halide perovskites (LHPs) that are used successfully in optolectronic applications remains hotly debated. Here, by using ultrafast X-ray transient absorption spectroscopy, we successfully tracked the fate of photogenerated charge carriers at room temperature within the thin films of two classic LHPs, namely, MAPbBr(3) (MA = CH3NH3) and FAPbBr(3) [FA = CH(NH2)(2)]. We clearly observed in both thin films that the hole polaron is formed by localizing the photogenerated hole at the Br 4p orbital and concurrently distorting the local structure surrounding the Br atom after the photoexcitation. Furthermore, the larger FA cation in the cavity of the [PbBr6](4-) octahedral framework induces a stronger hole polaron effect due to the hybridization of its p orbital into valence and conduction bands, correlating with the slower charge carrier recombination dynamics. Our direct experimental observation of the localized hole polaron in perovskites should advance the fundamental comprehension of charge carrier behavior within LHPs and their related devices.

引用

页码：6256 / 6261

页数：6

共 58 条

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