TY - JOUR
T1 - Slow thermal equilibration in methylammonium lead iodide revealed by transient mid-infrared spectroscopy
AU - Guo, Peijun
AU - Gong, Jue
AU - Sadasivam, Sridhar
AU - Xia, Yi
AU - Song, Tze Bin
AU - Diroll, Benjamin T.
AU - Stoumpos, Constantinos C.
AU - Ketterson, John B.
AU - Kanatzidis, Mercouri G.
AU - Chan, Maria K.Y.
AU - Darancet, Pierre
AU - Xu, Tao
AU - Schaller, Richard D.
N1 - Funding Information:
This work was performed at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, and supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. This material is based upon work supported by Laboratory Directed Research and Development (LDRD) funding from Argonne National Laboratory, provided by the Director, Office of Science, of the U.S. Department of Energy under contract DE-AC02-06CH11357. J.G. and T.X. acknowledge the financial support from the U.S. National Science Foundation (CBET-1150617). J.G. acknowledges the experimental support from Dr. Chhiu-Tsu Lin of Northern Illinois University. T.-B.S., C.C.S. and M.G.K. acknowledge the financial support from grant SC0012541 from the US Department of Energy, Office of Science (sample preparation).
Publisher Copyright:
© 2018 The Author(s).
PY - 2018/12/1
Y1 - 2018/12/1
N2 - Hybrid organic-inorganic perovskites are emerging semiconductors for cheap and efficient photovoltaics and light-emitting devices. Different from conventional inorganic semiconductors, hybrid perovskites consist of coexisting organic and inorganic sub-lattices, which present disparate atomic masses and bond strengths. The nanoscopic interpenetration of these disparate components, which lack strong electronic and vibrational coupling, presents fundamental challenges to the understanding of charge and heat dissipation. Here we study phonon population and equilibration processes in methylammonium lead iodide (MAPbI3) by transiently probing the vibrational modes of the organic sub-lattice following above-bandgap optical excitation. We observe inter-sub-lattice thermal equilibration on timescales ranging from hundreds of picoseconds to a couple of nanoseconds. As supported by a two-temperature model based on first-principles calculations, the slow thermal equilibration is attributable to the sequential phonon populations of the inorganic and organic sub-lattices, respectively. The observed long-lasting thermal non-equilibrium offers insights into thermal transport and heat management of the emergent hybrid material class.
AB - Hybrid organic-inorganic perovskites are emerging semiconductors for cheap and efficient photovoltaics and light-emitting devices. Different from conventional inorganic semiconductors, hybrid perovskites consist of coexisting organic and inorganic sub-lattices, which present disparate atomic masses and bond strengths. The nanoscopic interpenetration of these disparate components, which lack strong electronic and vibrational coupling, presents fundamental challenges to the understanding of charge and heat dissipation. Here we study phonon population and equilibration processes in methylammonium lead iodide (MAPbI3) by transiently probing the vibrational modes of the organic sub-lattice following above-bandgap optical excitation. We observe inter-sub-lattice thermal equilibration on timescales ranging from hundreds of picoseconds to a couple of nanoseconds. As supported by a two-temperature model based on first-principles calculations, the slow thermal equilibration is attributable to the sequential phonon populations of the inorganic and organic sub-lattices, respectively. The observed long-lasting thermal non-equilibrium offers insights into thermal transport and heat management of the emergent hybrid material class.
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U2 - 10.1038/s41467-018-05015-9
DO - 10.1038/s41467-018-05015-9
M3 - Article
C2 - 30022022
AN - SCOPUS:85050282443
VL - 9
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 2792
ER -