In-situ observation of trapped carriers in organic metal halide perovskite films with ultra-fast temporal and ultra-high energetic resolutions

Kanishka Kobbekaduwa, Shreetu Shrestha, Pan Adhikari, Exian Liu, Lawrence Coleman, Jianbing Zhang, Ying Shi, Yuanyuan ZHOU, Yehonadav Bekenstein, Feng Yan, Apparao M. Rao, Hsinhan Tsai, Matthew C. Beard, Wanyi Nie, Jianbo Gao*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

We in-situ observe the ultrafast dynamics of trapped carriers in organic methyl ammonium lead halide perovskite thin films by ultrafast photocurrent spectroscopy with a sub-25 picosecond time resolution. Upon ultrafast laser excitation, trapped carriers follow a phonon assisted tunneling mechanism and a hopping transport mechanism along ultra-shallow to shallow trap states ranging from 1.72–11.51 millielectronvolts and is demonstrated by time-dependent and independent activation energies. Using temperature as an energetic ruler, we map trap states with ultra-high energy resolution down to < 0.01 millielectronvolt. In addition to carrier mobility of ~4 cm2V−1s−1 and lifetime of ~1 nanosecond, we validate the above transport mechanisms by highlighting trap state dynamics, including trapping rates, de-trapping rates and trap properties, such as trap density, trap levels, and capture-cross sections. In this work we establish a foundation for trap dynamics in high defect-tolerant perovskites with ultra-fast temporal and ultra-high energetic resolution.

Original languageEnglish
Article number1636
Number of pages7
JournalNature Communications
Volume12
Issue number1
DOIs
Publication statusPublished - 12 Mar 2021

Scopus Subject Areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

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