Advanced

Light-induced defect healing and strong many-body interactions in formamidinium lead bromide perovskite nanocrystals

Ghosh, Supriya LU ; Shi, Qi LU ; Pradhan, Bapi ; Mushtaq, Aamir ; Acharya, Somobrata ; Karki, Khadga J. LU ; Pullerits, Tõnu LU and Pal, Suman Kalyan (2020) In Journal of Physical Chemistry Letters 11(4). p.1239-1246
Abstract

Organic lead halide perovskite (OLHP) nanocrystals (NCs) have paved the way to advanced optoelectronic devices through their extraordinary electrical and optical properties. However, understanding of the light-induced complex dynamic phenomena in OLHP NCs remains a subject of debate. Here we used wide field microscopy and time-resolved spectroscopy to correlate the local changes in photophysics and the dynamical behavior of photocarriers. We demonstrate that light-induced brightening of the photoluminescence from the formamidinium lead bromide NC films is related to the film preparation condition and reduction of trap density. The density of trap states is reduced via halide ion migration from interstitial position. Our femtosecond... (More)

Organic lead halide perovskite (OLHP) nanocrystals (NCs) have paved the way to advanced optoelectronic devices through their extraordinary electrical and optical properties. However, understanding of the light-induced complex dynamic phenomena in OLHP NCs remains a subject of debate. Here we used wide field microscopy and time-resolved spectroscopy to correlate the local changes in photophysics and the dynamical behavior of photocarriers. We demonstrate that light-induced brightening of the photoluminescence from the formamidinium lead bromide NC films is related to the film preparation condition and reduction of trap density. The density of trap states is reduced via halide ion migration from interstitial position. Our femtosecond transient absorption study identifies transient Stark effect due to the generation of hot carriers. Because of slow carrier trapping, Auger recombination through many-body carrier-carrier interactions dominates over trion recombination. This work presents unprecedented insights into the light-driven processes enabling better device design in the future.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physical Chemistry Letters
volume
11
issue
4
pages
8 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • pmid:31977225
  • scopus:85080841703
ISSN
1948-7185
DOI
10.1021/acs.jpclett.9b03818
language
English
LU publication?
yes
id
5094ac8b-bd81-48b1-bab1-e460e1c65284
date added to LUP
2020-03-18 15:33:45
date last changed
2020-10-20 01:38:17
@article{5094ac8b-bd81-48b1-bab1-e460e1c65284,
  abstract     = {<p>Organic lead halide perovskite (OLHP) nanocrystals (NCs) have paved the way to advanced optoelectronic devices through their extraordinary electrical and optical properties. However, understanding of the light-induced complex dynamic phenomena in OLHP NCs remains a subject of debate. Here we used wide field microscopy and time-resolved spectroscopy to correlate the local changes in photophysics and the dynamical behavior of photocarriers. We demonstrate that light-induced brightening of the photoluminescence from the formamidinium lead bromide NC films is related to the film preparation condition and reduction of trap density. The density of trap states is reduced via halide ion migration from interstitial position. Our femtosecond transient absorption study identifies transient Stark effect due to the generation of hot carriers. Because of slow carrier trapping, Auger recombination through many-body carrier-carrier interactions dominates over trion recombination. This work presents unprecedented insights into the light-driven processes enabling better device design in the future.</p>},
  author       = {Ghosh, Supriya and Shi, Qi and Pradhan, Bapi and Mushtaq, Aamir and Acharya, Somobrata and Karki, Khadga J. and Pullerits, Tõnu and Pal, Suman Kalyan},
  issn         = {1948-7185},
  language     = {eng},
  month        = {02},
  number       = {4},
  pages        = {1239--1246},
  publisher    = {The American Chemical Society (ACS)},
  series       = {Journal of Physical Chemistry Letters},
  title        = {Light-induced defect healing and strong many-body interactions in formamidinium lead bromide perovskite nanocrystals},
  url          = {http://dx.doi.org/10.1021/acs.jpclett.9b03818},
  doi          = {10.1021/acs.jpclett.9b03818},
  volume       = {11},
  year         = {2020},
}