Correlative analysis of CsPbBr2Hal (Hal = Cl, Br, I) melt-crystallization parameters

Metal halide perovskites (MHPs) are an exciting research topic as they have the potential to make solar cells that are both more efficient than current silicon-based designs and have a wider range of applications. In this work the crystallization of $\mathrm{CsPbBr}_{2} \mathrm{Hal}(\mathrm{Hal}=\mathrm{Cl}, \mathrm{Br}, \mathrm{I})$ halide perovskites melts were studied by the differential thermal analysis method. It was established that the crystallization of the $\mathrm{CsPbBr}_{2} \mathrm{Hal}(\mathrm{Hal}=\mathrm{Cl}, \mathrm{Br}, \mathrm{I})$ melts can be “hot” (at temperatures above the starting temperature for alloy melting) or with supercooling. The replacement of the bromine atom with another halogen atom leads to a shift of the dwell temperatures range, at which point the “hot” crystallization takes place, from 830-846 K for CsPbBr
3
to 807-832 K for CsPbBr
2
Cl and 741-768 K for CsPbBr
2
I. The activation energy of “hot” crystallization decreases in this order. A linear dependence between the pre-exponential factor ($\ln V_{\text {cryst, } 0}$) and the activation energy $\left(E_{\mathrm{a}}\right)$ of the crystallization process is revealed from experimental data, proving the compensation effect.