Assessing the viability of hydrogen-based perovskites for optoelectronic and thermoelectric applications via first principle modeling.

Context: In this study, we delve into the physical characteristics of six hydride perovskites of ABH-type materials (CsCaH, CsSrH, KMgH, LiBaH, NaBeH, and RbCaH). Our investigation primarily focuses on assessing their structural stability by determining the enthalpy of formation and examining the dispersion of phonons. Using band structure calculations, we discern the characteristics of semiconductors, observing a direct bandgap in all four perovskites except NaBeH and KMgH, which exhibit indirect gaps.