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Mechanistic insights into perovskite photoluminescence enhancement: light curing with oxygen can boost yield thousandfold

Tian, Yuxi LU ; Peter, Maximilian; Unger, Eva LU ; Qenawy, Mohamed LU ; Zheng, Kaibo LU ; Pullerits, Tönu LU ; Yartsev, Arkady LU ; Sundström, Villy LU and Scheblykin, Ivan LU (2015) In Physical Chemistry Chemical Physics 17(38). p.24978-24987
Abstract
A light-induced photoluminescence (PL) enhancement in surface-deposited methylammonium lead iodide (CH3NH3PbI3) perovskites was investigated in detail using time-resolved luminescence microscopy. We found the PL intensity to increase up to three orders of magnitude upon light illumination with an excitation power density of 0.01-1 W cm(-2). The PL enhancement is accompanied by an increase of the PL lifetime from several nanoseconds to several hundred nanoseconds and also by an increase of the initial amplitude of the PL decay. The latter suggests excited state quenching at the subpicosecond timescale. We propose a model where the trapping sites responsible for non-radiative charge recombination can be de-activated by a photochemical... (More)
A light-induced photoluminescence (PL) enhancement in surface-deposited methylammonium lead iodide (CH3NH3PbI3) perovskites was investigated in detail using time-resolved luminescence microscopy. We found the PL intensity to increase up to three orders of magnitude upon light illumination with an excitation power density of 0.01-1 W cm(-2). The PL enhancement is accompanied by an increase of the PL lifetime from several nanoseconds to several hundred nanoseconds and also by an increase of the initial amplitude of the PL decay. The latter suggests excited state quenching at the subpicosecond timescale. We propose a model where the trapping sites responsible for non-radiative charge recombination can be de-activated by a photochemical reaction involving oxygen. The reaction zone is spatially limited by the excitation light-penetration depth and diffusion length of the charge carriers. The latter increases in the course of the light-curing process making the reaction zone spreading from the surface towards the interior of the crystal. The PL enhancement can be reversed by switching on/off the excitation light or switching the atmosphere between oxygen and nitrogen. Slow diffusion of the reactants and products and equilibrium between the active and "cured" trapping sites are proposed to be the reasons for peculiar responses of PL to such varied experimental conditions. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Chemistry Chemical Physics
volume
17
issue
38
pages
24978 - 24987
publisher
Royal Society of Chemistry
external identifiers
  • pmid:26343504
  • wos:000361697400046
  • scopus:84942474277
ISSN
1463-9084
DOI
10.1039/c5cp04410c
language
English
LU publication?
yes
id
04b4966e-1f3b-45fe-acdc-4f787319711b (old id 8071062)
date added to LUP
2015-10-22 08:44:47
date last changed
2017-11-19 03:49:15
@article{04b4966e-1f3b-45fe-acdc-4f787319711b,
  abstract     = {A light-induced photoluminescence (PL) enhancement in surface-deposited methylammonium lead iodide (CH3NH3PbI3) perovskites was investigated in detail using time-resolved luminescence microscopy. We found the PL intensity to increase up to three orders of magnitude upon light illumination with an excitation power density of 0.01-1 W cm(-2). The PL enhancement is accompanied by an increase of the PL lifetime from several nanoseconds to several hundred nanoseconds and also by an increase of the initial amplitude of the PL decay. The latter suggests excited state quenching at the subpicosecond timescale. We propose a model where the trapping sites responsible for non-radiative charge recombination can be de-activated by a photochemical reaction involving oxygen. The reaction zone is spatially limited by the excitation light-penetration depth and diffusion length of the charge carriers. The latter increases in the course of the light-curing process making the reaction zone spreading from the surface towards the interior of the crystal. The PL enhancement can be reversed by switching on/off the excitation light or switching the atmosphere between oxygen and nitrogen. Slow diffusion of the reactants and products and equilibrium between the active and "cured" trapping sites are proposed to be the reasons for peculiar responses of PL to such varied experimental conditions.},
  author       = {Tian, Yuxi and Peter, Maximilian and Unger, Eva and Qenawy, Mohamed and Zheng, Kaibo and Pullerits, Tönu and Yartsev, Arkady and Sundström, Villy and Scheblykin, Ivan},
  issn         = {1463-9084},
  language     = {eng},
  number       = {38},
  pages        = {24978--24987},
  publisher    = {Royal Society of Chemistry},
  series       = {Physical Chemistry Chemical Physics},
  title        = {Mechanistic insights into perovskite photoluminescence enhancement: light curing with oxygen can boost yield thousandfold},
  url          = {http://dx.doi.org/10.1039/c5cp04410c},
  volume       = {17},
  year         = {2015},
}