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Reversible Crystal–Glass Transition in a Metal Halide Perovskite

December 6, 2020

A 2D metal halide perovskite (MHP) was structurally tailored using bulky chiral organic cations to exhibit an unusual confluence of exceptionally low melting temperature (175 °C) and inhibited crystallization. The chiral MHP can thus be melt‐quenched into a stable glassy state, otherwise inhibited in the analogous racemic MHP.

Scientific Achievement

We demonstrated glass formation and a reversible glass-crystal transition in a 2D MHP with distinct optoelectronic properties in respective phases.

Significance and Impact

2D halide perovskites are introduced into the field of semi-conducting glasses through deliberate synthetic design of the hybrid structure, resulting in facile and reversible glass–crystalline switching under moderate thermal cycling for prospective application in memory, computing, nonlinear optics, communication, and renewable energy.

Research Details

  • Established design rules for achieving crystal-glass transition in 2D MHPs, through the example of [S-(−)-1-(1-naphthyl)ethyl-ammonium]2PbBr4 (S-NPB), with each phase offering a distinct optical absorbance profile (top panel).
  • Demonstrated reversibility in the crystal-glass transition using melt-quenching and moderate heat treatment (top panel).
  • Evaluated characteristic temperatures—i.e, Tg (glass transition), Tx (crystallization), Tm (melting) and Td (degradation)—for glass-crystal transition, using thermal analysis (bottom panel).

DOI: 10.1002/adma.202005868

Related People

David Mitzi
Duke University

Charts and images showing glass perovskite transition temperatures--21 degrees Celsius, 90 degrees Celsius, and 140 degrees Celsius--into crystalline perovskite; and the crystalline perovskite transition temperatures--140 degrees Celsius, 190 degrees Celsius, and 21 degrees Celsius--into glass perovskite.Chart showing the temperatures of glass transition, crystallization, melting, and degradation at heat flow and weight loss.