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Title: Ionic and Optical Properties of Methylammonium Lead Iodide Perovskite across the Tetragonal-Cubic Structural Phase Transition

Practical hybrid perovskite solar cells (PSCs) must endure temperatures above the tetragonal-cubic structural phase transition of methylammonium lead iodide (MAPbI3). However, the ionic and optical properties of MAPbI3 in such a temperature range, and particularly, dramatic changes in these properties resulting from a structural phase transition, are not well studied. Herein, we report a striking contrast at approximately 45 degrees C in the ionic/electrical properties of MAPbl3 owing to a change of the ion activation energy from 0.7 to 0.5 eV, whereas the optical properties exhibit no particular transition except for the steady increase of the bandgap with temperature. These observations can be explained by the 'continuous' nature of perovskite phase transition. We speculate that the critical temperature at which the ionic/electrical properties change, although related to crystal symmetry variation, is not necessarily the same temperature as when tetragonal-cubic structural phase transition occurs.
 [1] ;  [1] ;  [2] ;  [1] ;  [2] ;  [1]
  1. Department of Electrical and Computer Engineering and Nano Tech Center, Texas Tech University, Lubbock Texas 79409 USA
  2. Chemistry and Nanoscience Center, National Renewable Energy Laboratory, Golden Colorado 80401 USA
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 1864-5631
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: ChemSusChem; Journal Volume: 9; Journal Issue: 18
ChemPubSoc Europe
Research Org:
NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States))
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
Country of Publication:
United States
14 SOLAR ENERGY; 36 MATERIALS SCIENCE cubic; optoelectronic properties; tetragonal; perovskite; phase transition