Structural, Electronic, and Thermoelectric Insights into the Novel K₂OsCl₃Ag₃ and Rb₂OsCl₃Ag₃ Perovskites

The field of perovskites continues to advance each day, with new materials being discovered in order to eliminate the toxic and less efficient ones. Some of the challenges currently facing the perovskite industry include coming up with materials with higher electrical conductivity and lower thermal conductivity, as well as p-type semiconductors. In an attempt to address these challenges, this study modeled two novel perovskites from potassium hexachloroosmate (VI) (K₂OsCl₆) by replacing some of the chlorine atoms with those of silver, then characterized their structural, electronic (using both conventional and hybrid functionals), and thermoelectric properties using <i>Quantum Espresso</i> and <i>BoltzTrap2</i> codes. The calculations were performed within the framework of density functional theory. The results showed that the novel materials exhibited higher density, lower thermal conductivity, lower band gaps, and positive Hall coefficient, unlike the K₂OsCl₆ sample. These materials can thus be used in areas such as in p–n junctions, thermoelectric devices, and optoelectronic devices. However, since this study was purely computational, the properties need to be verified through an experimental study.