Phys.org March 12, 2021
An international team of researchers (USA – Clemson University, Los Alamos National Laboratory, University of Alabama, China) observed the ultrafast dynamics of trapped carriers in organic methyl ammonium lead halide perovskite thin films by ultrafast photocurrent spectroscopy. Upon ultrafast laser excitation, trapped carriers followed a phonon assisted tunneling mechanism and a hopping transport mechanism along ultra-shallow to shallow trap states ranging from 1.72–11.51 millielectronvolts. They validated the 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. The work establishes a foundation for trap dynamics in high defect-tolerant perovskites with ultra-fast temporal and ultra-high energetic resolution…read more. Open Access TECHNICAL ARTICLE
Experimental schematic setup of UPCS. Credit: Nature Communications volume 12, Article number: 1636 (2021)