TY - JOUR
T1 - Energetics, Structures, and Phase Transitions of Cubic and Orthorhombic Cesium Lead Iodide (CsPbI3) Polymorphs
AU - Wang, Bin
AU - Novendra, Novendra
AU - Navrotsky, Alexandra
N1 - Funding Information:
The authors thank Lili Wu for helpful discussions in designing experiments, Shuhao Yang for assistance with crystal structure visualization, and Tamilarasan Subramani for discussion during paper revision. The work was supported by the U.S. Department of Energy Office of Basic Energy Science, Grant DE-FG02-03ER46053.
Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/9/18
Y1 - 2019/9/18
N2 - Cesium lead iodide (CsPbI3) perovskite has shown great potential as a light absorbing material for solar cell applications. Despite intense research leading to increasing power conversion efficiency, a major problem concerning CsPbI3 lies in the long term stability and interconversion between different CsPbI3 polymorphs, a subject barely studied from the thermodynamic perspective. We report the formation enthalpies of two CsPbI3 polymorphs, α and δCsPbI3, using a combination of room temperature solution calorimetry in dimethyl sulfoxide (DMSO) and differential scanning calorimetry. We show that both polymorphs are stable with respect to their binary halides and confirm that the α-phase is a high temperature polymorph, metastable under ambient conditions. This work sheds light on patterns in polymorphism, possible decomposition reactions, materials stability, and compatibility within halide perovskites and related systems. Thermodynamic instability near ambient temperature of functional perovskites may be a general phenomenon related to their vibrational density of states.
AB - Cesium lead iodide (CsPbI3) perovskite has shown great potential as a light absorbing material for solar cell applications. Despite intense research leading to increasing power conversion efficiency, a major problem concerning CsPbI3 lies in the long term stability and interconversion between different CsPbI3 polymorphs, a subject barely studied from the thermodynamic perspective. We report the formation enthalpies of two CsPbI3 polymorphs, α and δCsPbI3, using a combination of room temperature solution calorimetry in dimethyl sulfoxide (DMSO) and differential scanning calorimetry. We show that both polymorphs are stable with respect to their binary halides and confirm that the α-phase is a high temperature polymorph, metastable under ambient conditions. This work sheds light on patterns in polymorphism, possible decomposition reactions, materials stability, and compatibility within halide perovskites and related systems. Thermodynamic instability near ambient temperature of functional perovskites may be a general phenomenon related to their vibrational density of states.
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U2 - 10.1021/jacs.9b05924
DO - 10.1021/jacs.9b05924
M3 - Article
C2 - 31487167
AN - SCOPUS:85072367226
SN - 0002-7863
VL - 141
SP - 14501
EP - 14504
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 37
ER -