Melting and Glass Formation in Halide Perovskites

Halide perovskites represent a highly regarded class of optoelectronic semiconductors, demonstrating unprecedented performance in photovoltaic, light-emitting, and sensing devices. Despite their invention in 1892, almost exclusively, all the research (~50,000 publications) has focused on their crystalline state, characterized by precise atomic arrangements. Introducing controlled disorder through a melt and/or glassy state lacking significant long-range periodicity unlocks new avenues for applications, reminiscent of the transformative impact provided by glassy chalcogenides in commercial memory and computing applications. This dissertation introduces halide perovskites into the family of glass forming semiconductors, presenting various halide perovskites with adjustable melting, glass-forming, and glass-crystallization properties. These properties were thoroughly investigated using a comprehensive approach encompassing structural, thermal, mechanical, optoelectronic, spectroscopic, and numerical modeling techniques. The study highlights the principles involved in creating low-melting-temperature and switchable crystalline/glassy states, underscoring the critical importance of investigating these states for future applications in memory, computing, energy storage, reconfigurable metamaterials and photonic devices.