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Title: Electrochemical Hole Injection Selectively Expels Iodide from Mixed Halide Perovskite Films

Abstract

Halide ion mobility in metal halide perovskites remains an intriguing phenomenon, influencing their optical and photovoltaic properties. Selective injection of holes through electrochemical anodic bias has allowed us to probe the effect of hole trapping at iodide (0.9 V) and bromide (1.15 V) in mixed halide perovskite (CH 3NH 3PbBr 1.5I 1.5) films. Upon trapping holes at the iodide site, the iodide gradually gets expelled from the mixed halide film (as iodine and/or triiodide ion), leaving behind re-formed CH 3NH 3PbBr 3 domains. The weakening of the Pb-I bond following the hole trapping (oxidation of the iodide site) and its expulsion from the lattice in the form of iodine provided further insight into the photoinduced segregation of halide ions in mixed halide perovskite films. Transient absorption spectroscopy revealed that the iodide expulsion process leaves a defect-rich perovskite lattice behind as charge carrier recombination in the re-formed lattice is greatly accelerated. The selective mobility of iodide species provides insight into the photoinduced phase segregation and its implication in the stable operation of perovskite solar cells.

Authors:
ORCiD logo [1];  [2]; ORCiD logo [3]; ORCiD logo [4]; ORCiD logo [5]; ORCiD logo [6]
  1. Univ. of Szeged (Hungary); ELI-ALPS Research Institute, Szeged (Hungary); Univ. of Notre Dame, IN (United States)
  2. Univ. of Szeged (Hungary)
  3. Univ. of Perugia, Via Elce di Sotto (Italy); Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO), CNR-ISTM, Via Elce di Sotto (Italy); CompuNet, Istituto Italiano di Tecnologia, Genova (Italy)
  4. Computational Laboratory for Hybrid/Organic Photovoltaics (CLHYO), CNR-ISTM, Via Elce di Sotto (Italy); CompuNet, Istituto Italiano di Tecnologia, Genova (Italy)
  5. Univ. of Notre Dame, IN (United States)
  6. Univ. of Szeged (Hungary); ELI-ALPS Research Institute, Szeged (Hungary)
Publication Date:
Research Org.:
Univ. of Szeged (Hungary)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division
OSTI Identifier:
1530479
Alternate Identifier(s):
OSTI ID: 1542124
Grant/Contract Number:  
FC02-04ER15533
Resource Type:
Published Article
Journal Name:
Journal of the American Chemical Society
Additional Journal Information:
Journal Volume: 141; Journal Issue: 27; Journal ID: ISSN 0002-7863
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Samu, Gergely F., Balog, Ádám, De Angelis, Filippo, Meggiolaro, Daniele, Kamat, Prashant V., and Janáky, Csaba. Electrochemical Hole Injection Selectively Expels Iodide from Mixed Halide Perovskite Films. United States: N. p., 2019. Web. doi:10.1021/jacs.9b04568.
Samu, Gergely F., Balog, Ádám, De Angelis, Filippo, Meggiolaro, Daniele, Kamat, Prashant V., & Janáky, Csaba. Electrochemical Hole Injection Selectively Expels Iodide from Mixed Halide Perovskite Films. United States. doi:10.1021/jacs.9b04568.
Samu, Gergely F., Balog, Ádám, De Angelis, Filippo, Meggiolaro, Daniele, Kamat, Prashant V., and Janáky, Csaba. Wed . "Electrochemical Hole Injection Selectively Expels Iodide from Mixed Halide Perovskite Films". United States. doi:10.1021/jacs.9b04568.
@article{osti_1530479,
title = {Electrochemical Hole Injection Selectively Expels Iodide from Mixed Halide Perovskite Films},
author = {Samu, Gergely F. and Balog, Ádám and De Angelis, Filippo and Meggiolaro, Daniele and Kamat, Prashant V. and Janáky, Csaba},
abstractNote = {Halide ion mobility in metal halide perovskites remains an intriguing phenomenon, influencing their optical and photovoltaic properties. Selective injection of holes through electrochemical anodic bias has allowed us to probe the effect of hole trapping at iodide (0.9 V) and bromide (1.15 V) in mixed halide perovskite (CH3NH3PbBr1.5I1.5) films. Upon trapping holes at the iodide site, the iodide gradually gets expelled from the mixed halide film (as iodine and/or triiodide ion), leaving behind re-formed CH3NH3PbBr3 domains. The weakening of the Pb-I bond following the hole trapping (oxidation of the iodide site) and its expulsion from the lattice in the form of iodine provided further insight into the photoinduced segregation of halide ions in mixed halide perovskite films. Transient absorption spectroscopy revealed that the iodide expulsion process leaves a defect-rich perovskite lattice behind as charge carrier recombination in the re-formed lattice is greatly accelerated. The selective mobility of iodide species provides insight into the photoinduced phase segregation and its implication in the stable operation of perovskite solar cells.},
doi = {10.1021/jacs.9b04568},
journal = {Journal of the American Chemical Society},
number = 27,
volume = 141,
place = {United States},
year = {2019},
month = {6}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1021/jacs.9b04568

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