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Title: Nanosecond, Time-Resolved Shift of the Photoluminescence Spectra of Organic, Lead-Halide Perovskites Reveals Structural Features Resulting from Excess Organic Ammonium Halide

Abstract

The effort to drive solution-based perovskite solar cells toward higher efficiency has been considerable, reaching over 24%. Such progress has been made possible by the low-energy barrier to crystallization. The low-energy barrier in the reverse direction, however, also renders them susceptible to dissociation from heat, moisture, and photoexcitation. Consequently, studies that provide information on the stability of perovskites are of considerable importance. It has been reported that perovskite crystals formed using different stoichiometries of the organic precursors and metal halide are equivalent. Our findings, however, suggest that the difference in reaction pathways affects the quality of the final crystal and that changes in morphology and the production of any defects can lead to differences in behavior under illumination. Here, we present photoluminescence spectra subsequent to nanosecond photoexcitation of perovskites synthesized under various conditions. Our results indicate that the presence of excess precursors (i.e., CH 3NH 3X, X = I and surfactant) gives rise to an ~20 ns relaxation time with which the photoluminescence spectrum achieves its equilibrium value. This relaxation is absent in bulk, polycrystalline materials. This is, to our knowledge, the first report of the ~20 ns relaxation time, which we attribute to cation migration. Furthermore, these structural changesmore » are not detectable subsequent to photoexcitation by X-ray diffraction nor are they detectable by in situ X-ray diffraction during photoexcitation.« less

Authors:
 [1];  [2];  [2];  [2]; ORCiD logo [2]; ORCiD logo [2]; ORCiD logo [2]
  1. Ames Lab., and Iowa State Univ., Ames, IA (United States); IIEST Shibpur, West Bengal (India)
  2. Ames Lab., and Iowa State Univ., Ames, IA (United States)
Publication Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division
OSTI Identifier:
1581592
Report Number(s):
IS-J-10116
Journal ID: ISSN 1932-7447
Grant/Contract Number:  
AC02-07CH11358
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 123; Journal Issue: 49; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Hydrocarbons; Precursors; Aromatic compounds; Cations; Perovskites

Citation Formats

Bhattacharjee, Ujjal, Men, Long, Mai, Han, Freppon, Daniel, Smith, Emily A., Vela, Javier, and Petrich, Jacob W. Nanosecond, Time-Resolved Shift of the Photoluminescence Spectra of Organic, Lead-Halide Perovskites Reveals Structural Features Resulting from Excess Organic Ammonium Halide. United States: N. p., 2019. Web. doi:10.1021/acs.jpcc.9b07913.
Bhattacharjee, Ujjal, Men, Long, Mai, Han, Freppon, Daniel, Smith, Emily A., Vela, Javier, & Petrich, Jacob W. Nanosecond, Time-Resolved Shift of the Photoluminescence Spectra of Organic, Lead-Halide Perovskites Reveals Structural Features Resulting from Excess Organic Ammonium Halide. United States. doi:10.1021/acs.jpcc.9b07913.
Bhattacharjee, Ujjal, Men, Long, Mai, Han, Freppon, Daniel, Smith, Emily A., Vela, Javier, and Petrich, Jacob W. Sat . "Nanosecond, Time-Resolved Shift of the Photoluminescence Spectra of Organic, Lead-Halide Perovskites Reveals Structural Features Resulting from Excess Organic Ammonium Halide". United States. doi:10.1021/acs.jpcc.9b07913.
@article{osti_1581592,
title = {Nanosecond, Time-Resolved Shift of the Photoluminescence Spectra of Organic, Lead-Halide Perovskites Reveals Structural Features Resulting from Excess Organic Ammonium Halide},
author = {Bhattacharjee, Ujjal and Men, Long and Mai, Han and Freppon, Daniel and Smith, Emily A. and Vela, Javier and Petrich, Jacob W.},
abstractNote = {The effort to drive solution-based perovskite solar cells toward higher efficiency has been considerable, reaching over 24%. Such progress has been made possible by the low-energy barrier to crystallization. The low-energy barrier in the reverse direction, however, also renders them susceptible to dissociation from heat, moisture, and photoexcitation. Consequently, studies that provide information on the stability of perovskites are of considerable importance. It has been reported that perovskite crystals formed using different stoichiometries of the organic precursors and metal halide are equivalent. Our findings, however, suggest that the difference in reaction pathways affects the quality of the final crystal and that changes in morphology and the production of any defects can lead to differences in behavior under illumination. Here, we present photoluminescence spectra subsequent to nanosecond photoexcitation of perovskites synthesized under various conditions. Our results indicate that the presence of excess precursors (i.e., CH3NH3X, X = I and surfactant) gives rise to an ~20 ns relaxation time with which the photoluminescence spectrum achieves its equilibrium value. This relaxation is absent in bulk, polycrystalline materials. This is, to our knowledge, the first report of the ~20 ns relaxation time, which we attribute to cation migration. Furthermore, these structural changes are not detectable subsequent to photoexcitation by X-ray diffraction nor are they detectable by in situ X-ray diffraction during photoexcitation.},
doi = {10.1021/acs.jpcc.9b07913},
journal = {Journal of Physical Chemistry. C},
number = 49,
volume = 123,
place = {United States},
year = {2019},
month = {11}
}

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This content will become publicly available on November 16, 2020
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