Experimental and DFT study of structural, optical and piezoelectric properties of perovskite SmTaO₃ for optoelectronic applications

Perovskite materials have garnered significant attention due to their versatile structural, electronic, and functional properties, making them ideal candidates for a wide range of technological applications. In this study, we investigate the structural, mechanical, electronic, optical, and piezoelectric properties of SmTaO₃ perovskite using a combination of experimental techniques and first-principles calculations. X-ray diffraction analysis confirmed the orthorhombic perovskite structure with a Pbnm space group, supported by high crystallinity and minimal defect levels as indicated by dislocation density and strain analysis. Scanning electron microscopy revealed irregular grain morphology, while energy-dispersive X-ray spectroscopy validated the elemental purity of the sample. Besides, the formation energy is calculated to theoretically confirm the stability of SmTaO₃. The material's electronic structure demonstrated metallic behavior with overlapping valence and conduction bands at the Fermi level. Mechanical property analysis highlighted structural stability and moderate anisotropy, with optical studies revealing high UV reflectivity and absorption. Notably, the piezoelectric stress coefficients showed significant anisotropy, suggesting SmTaO₃'s potential for applications in sensors and energy harvesting devices. These findings establish SmTaO₃ as a promising material for optoelectronic devices.