Polymorphism in metal halide perovskites

Aida Alaei, Abigail Circelli, Yihang Yuan, Yi Yang, Stephanie S. Lee

Research output: Contribution to journalReview articlepeer-review


Metal halide perovskites (MHPs) are frontrunners among solution-processable materials for lightweight, large-area and flexible optoelectronics. These materials, with the general chemical formula AMX3, are structurally complex, undergoing multiple polymorph transitions as a function of temperature and pressure. In this review, we provide a detailed overview of polymorphism in three-dimensional MHPs as a function of composition, with A = Cs+, MA+, or FA+, M = Pb2+ or Sn2+, and X = Cl-, Br-, or I-. In general, perovskites adopt a highly symmetric cubic structure at elevated temperatures. With decreasing temperatures, the corner-sharing MX6 octahedra tilt with respect to one another, resulting in multiple polymorph transitions to lower-symmetry tetragonal and orthorhombic structures. The temperatures at which these phase transitions occur can be tuned via different strategies, including crystal size reduction, confinement in scaffolds and (de-)pressurization. As discussed in the final section of this review, these solid-state phase transformations can significantly affect optoelectronic properties. Understanding factors governing these transitions is thus critical to the development of high-performance, stable devices.

Original languageEnglish (US)
Pages (from-to)47-63
Number of pages17
JournalMaterials Advances
Issue number1
StatePublished - 2021

ASJC Scopus subject areas

  • Chemistry (miscellaneous)
  • General Materials Science


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