Tailoring the electronic, optical and mechanical properties of KMgH₃ and RbCaH₃ perovskite hydrides without and with Samarium

Perovskite hydrides such as KMgH₃ and RbCaH₃ have been proven to be an attractive candidate for good application prospects in optoelectronic devices and conversion energy. Doping these perovskites with rare earth has turned into a progressively essential way to improve luminescence and photo-conversion of devices. In this work, the ab-initio calculations have been carried out to explore the structural, electronic, optical, and mechanical properties of both KMgH₃ and RbCaH₃ without and with Sm based on generalized gradient approximation functional within the framework of DFT including the spin−orbit coupling. It is found that doping the perovskites with Sm depicts substantially modification in electronic behavior leading increased bandgap energy as well as the carrier effective masses with increasing Sm concentrations for the case of KMgH₃, while it has been reduced for RbCaH₃. In addition, the optical investigation reveals a blue-shift phenomenon from absorption coefficient spectra, which is owing to the Sm doping into KMgH₃; combined with a minimum absorption in visible spectrum for pure KMgH₃ perovskite. Besides, we denote a maximum absorption in the UV region of the doped RbCaH₃. Furthermore, the mechanical analysis exhibits that these perovskites are hard and stiffer, especially KMgH₃ hydride systems. These outcomes may conduct and give a reliable reference for experimenters to design novel perovskite hydrides toward improving optoelectronic performances.