Reversible Crystal–Glass Transition in a Metal Halide Perovskite

Abstract

Crystalline metal halide perovskites (MHPs) have provided unprecedented advances in interdisciplinary fields of materials, electronics, and photonics. While crystallinity offers numerous advantages, the ability to access a glassy state with distinct properties provides unique opportunities to extend the associated structure–property relationship, as well as broaden the application space for MHPs. Amorphous analogs for MHPs have so far been restricted to high pressures, limiting detailed studies and applications. Here, a 2D MHP is 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. Facile and reversible switching between glassy and crystalline states is demonstrated for the chiral MHP, each with distinct optoelectronic character, opening new opportunities for applications including, for example nonvolatile memory, optical communication, and neuromorphic computing.

Principles of melting in hybrid organic–inorganic perovskite and polymorphic ABX3 structures

“…Interestingly, cooling of these high temperature liquids back to room temperature results in glass formation, like the recent example in two-dimensional perovskites. 21 Furthermore, unlike existing glasses formed by melt-quenching MOFs, [22][23][24][25] those formed from HOIPs exhibit interesting electronic/phononic properties with potential applications in e.g. thermoelectrics.…”

Thermodynamic stability screening of IR-photonic processed multication halide perovskite thin films

“…61,62 The volatility of MA also becomes apparent when examining the transition to the PbI 2 classication, where a higher MA concentration leads to perovskite decomposition at an earlier time. 63,64 We analyzed in more detail each of the 14 compositions annealed at the optimal time, t f ¼ 1.4 s, that crystallize in the perovskite phase. Fig.…”

Advancing the Mechanical Performance of Glasses: Perspectives and Challenges

“…As the most recent example of hybrid glasses, glassy materials derived from organic-inorganic perovskites have been reported. [229,230] For example, dicyanamide-based perovskite glasses have been discovered with Young's modulus of around 6-7 GPa, intermediate between typical values for organic and inorganic materials. [230] Overall, these studies suggest that some improvement of hybrid glass mechanical properties may be needed depending on the application, but the chemical flexibility of both organic and inorganic building units should allow for this.…”

“…As the most recent example of hybrid glasses, glassy materials derived from organic–inorganic perovskites have been reported. [ 229,230 ] For example, dicyanamide‐based perovskite glasses have been discovered with Young's modulus of around 6–7 GPa, intermediate between typical values for organic and inorganic materials. [ 230 ]…”