Influence of Pressure on Structural, Electronic, Optical, and Elastic Properties of Lead-Free Chalcogen Perovskite LaLuS3 via First-Principles Calculations: Implications for Optoelectronic Applications

Abstract Chalcogen perovskites have garnered increasing attention as promising materials for optoelectronic applications. In this study, we employed the first-principles method to investigate the structural, electronic, optical, and elastic properties of LaLuS3 under hydrostatic pressure at various levels. Through a thorough analysis of the calculated electronic structures, we observed that LaLuS3 exhibits direct band gaps, with the magnitudes of these gaps changing as the pressure varied. Specifically, the band gaps decrease by 2.19 eV, 2.025 eV, 1.365 eV, and 0.6043 eV at hydrostatic pressures of 0%, 10%, 20%, and 30% GPa, respectively. Furthermore, we observed shifts in the conduction band minimum and valence band maximum positions, indicating the potential of LaLuS3 for perovskite-based devices. This suggests that external pressure can serve as a powerful tool for designing new functional materials with intriguing properties. Our investigation also revealed promising optical properties of LaLuS3 under high pressures, further affirming its potential for optoelectronic and solar cell applications. The optical functions of the material are enhanced with increasing pressure, particularly in the ultraviolet range, highlighting its suitability for a wide range of optoelectronic devices. Moreover, while maintaining mechanical stability, hydrostatic pressure exerts a significant influence on the mechanical properties of LaLuS3. Lastly, our calculations on anisotropy demonstrate that applied pressure can enhance the anisotropic nature of LaLuS3. This comprehensive study underscores the efficacy of hydrostatic pressure as a systematic approach to modifying the photovoltaic performance of halide perovskites.