Fundamental carrier lifetime exceeding 1 µs in Cs2AgBiBr6 double perovskite
Author(s)
Type
Journal Article
Abstract
There is current interest in finding nontoxic alternatives to lead‐halide perovskites for optoelectronic applications. Silver–bismuth double perovskites have recently gained attention, but evaluating their carrier lifetime and recombination mechanisms from photoluminescence measurements is challenging due to their indirect bandgap. In this work, transient absorption spectroscopy is used to directly track the photocarrier population in Cs2AgBiBr6 by measuring the ground state bleach dynamics. A small initial drop is resolved in the ground state bleach on a picosecond timescale, after which the remaining photocarriers decay monoexponentially with a lifetime of 1.4 µs. The majority of the early‐time decay is attributed to hot‐carrier thermalization from the direct transition to the indirect bandgap, and the 1.4 µs lifetime represents the recombination of most photocarriers. From this lifetime, a steady‐state excess carrier density of 2.2 × 1016 cm−3 under 1 sun is calculated, which is an order of magnitude larger than that for methylammonium lead iodide, suggesting that charge transport and extraction can be efficient in Cs2AgBiBr6 solar cells.
Date Issued
2018-08-09
Date Acceptance
2018-04-24
Citation
Advanced Materials Interfaces, 2018, 5 (15), pp.1-8
ISSN
2196-7350
Publisher
Wiley
Start Page
1
End Page
8
Journal / Book Title
Advanced Materials Interfaces
Volume
5
Issue
15
Copyright Statement
© 2018 The Authors. Published by WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Sponsor
Magdalene College, University of Cambridge
Identifier
https://onlinelibrary.wiley.com/doi/full/10.1002/admi.201800464
Publication Status
Published
Date Publish Online
2018-05-22