Anomalous structural evolution and glassy lattice in mixed‐halide hybrid perovskites
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Date
2022-05
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley
Abstract
Hybrid halide perovskites have emerged as highly promising photovoltaic materials because of their exceptional optoelectronic properties, which are often optimized via compositional engineering like mixing halides. It is well established that hybrid perovskites undergo a series of structural phase transitions as temperature varies. In this work, the authors find that phase transitions are substantially suppressed in mixed‐halide hybrid perovskite single crystals of MAPbI3‐xBrx (MA = CH3NH3+ and x = 1 or 2) using a complementary suite of diffraction and spectroscopic techniques. Furthermore, as a general behavior, multiple crystallographic phases coexist in mixed‐halide perovskites over a wide temperature range, and a slightly distorted monoclinic phase, hitherto unreported for hybrid perovskites, is dominant at temperatures above 100 K. The anomalous structural evolution is correlated with the glassy behavior of organic cations and optical phonons in mixed‐halide perovskites. This work demonstrates the complex interplay between composition engineering and lattice dynamics in hybrid perovskites, shedding new light on their unique properties. © 2022 The Authors. Small published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Description
Keywords
Perovskites, Halides, Materials, Temperature range, Crystallography, Evolution, Hybridization, Crystal lattices, Absorption
Citation
Shahrokhi, S., Dubajic, M., Dai, Z.-Z., Bhattacharyya, S., Mole, R. A., Rule, K. C., Bhadbhade, M., Tian, R., Mussakhanuly, N., Guan, X., Yin, Y., Nielsen, M. P., Hu, L., Lin, C.-H., Chang, S. L. Y., Wang, D., Kabakova, I. V., Conibeer, G., Bremner, S., Lim X.-G., Cazorla, C., & Wu, T. (2022). Anomalous structural evolution and glassy lattice in mixed‐halide hybrid perovskites. Small, 18(21), 2200847. doi:10.1002/smll.202200847