Issue 41, 2023

Beneficial effects of tensile strain on charge carrier lifetime in metal halide perovskites containing halogen vacancies

Abstract

We report a time-domain ab initio investigation of the tensile strain-dependent nonradiative charge recombination in methylammonium lead halide (MAPbI3) perovskites containing halogen vacancy defects. Our results show that applying tensile strain increases the Pb–Pb distance across the vacancy site and weakens the hybridization of Pb-p dangling states, leading to an upshift of the defect level. Shallower defect levels are beneficial to the suppression of trap-assisted electron–hole (e–h) recombination. Interestingly, strained systems exhibit a smaller dynamical disorder owing to the decreased vibrational anharmonicity, leading to weakened electron–vibrational interaction. Moreover, the bandgap increases with tensile strain because the valence band shows more anti-bonding character than the conduction band. Hence, direct e–h recombination bypassing the trap state is alleviated. The synergistic effects of tensile strain on e–h recombination, through and bypassing the trap state, prolong the charge carrier lifetimes by an order of magnitude under moderate strain. Our time-domain atomistic investigation highlights the importance of vibrational anharmonicity in charge carrier lifetime and provides fundamental insights into the passivation mechanism of halogen vacancies by tensile strain, which are of fundamental interest for further optimization of perovskite solar cells and other related devices.

Graphical abstract: Beneficial effects of tensile strain on charge carrier lifetime in metal halide perovskites containing halogen vacancies

Supplementary files

Article information

Article type
Paper
Submitted
08 Aug. 2023
Accepted
18 Sept. 2023
First published
19 Sept. 2023

J. Mater. Chem. C, 2023,11, 14097-14107

Beneficial effects of tensile strain on charge carrier lifetime in metal halide perovskites containing halogen vacancies

Z. Wang, P. Zhang, W. Wei and W. Li, J. Mater. Chem. C, 2023, 11, 14097 DOI: 10.1039/D3TC02828C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements