TY - JOUR
T1 - Direct calorimetric verification of thermodynamic instability of lead halide hybrid perovskites
AU - Nagabhushana, G. P.
AU - Shivaramaiah, Radha
AU - Navrotsky, Alexandra
N1 - Publisher Copyright:
© 2016, National Academy of Sciences. All rights reserved.
PY - 2016/7/12
Y1 - 2016/7/12
N2 - Hybrid perovskites, especially methylammonium lead iodide (MAPbI3), exhibit excellent solar power conversion efficiencies. However, their application is plagued by poor chemical and structural stability. Using direct calorimetric measurement of heats of formation, MAPbI3 is shown to be thermodynamically unstable with respect to decomposition to lead iodide and methylammonium iodide, even in the absence of ambient air or light or heat-induced defects, thus limiting its long-term use in devices. The formation enthalpy from binary halide components becomes less favorable in the order MAPbCl3, MAPbBr3, MAPbI3, with only the chloride having a negative heat of formation. Optimizing the geometric match of constituents as measured by the Goldschmidt tolerance factor provides a potentially quantifiable thermodynamic guide for seeking chemical substitutions to enhance stability.
AB - Hybrid perovskites, especially methylammonium lead iodide (MAPbI3), exhibit excellent solar power conversion efficiencies. However, their application is plagued by poor chemical and structural stability. Using direct calorimetric measurement of heats of formation, MAPbI3 is shown to be thermodynamically unstable with respect to decomposition to lead iodide and methylammonium iodide, even in the absence of ambient air or light or heat-induced defects, thus limiting its long-term use in devices. The formation enthalpy from binary halide components becomes less favorable in the order MAPbCl3, MAPbBr3, MAPbI3, with only the chloride having a negative heat of formation. Optimizing the geometric match of constituents as measured by the Goldschmidt tolerance factor provides a potentially quantifiable thermodynamic guide for seeking chemical substitutions to enhance stability.
KW - Enthalpy of formation
KW - Hybrid halide perovskites
KW - Solar cells
KW - Thermodynamic instability
KW - Tolerance factor
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U2 - 10.1073/pnas.1607850113
DO - 10.1073/pnas.1607850113
M3 - Article
AN - SCOPUS:84978037217
SN - 0027-8424
VL - 113
SP - 7717
EP - 7721
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 28
ER -