A Novel SiGaS Monolayer for Photovoltaic Applications.

Two-dimensional materials have shown potential applications ranging from electronic devices to solar panels as their properties significantly differ from those of bulk materials. Herein, density functional theory is used to investigate the structural, electronic, optical, power conversion efficiency and Shockley-Queisser limit, and thermodynamic properties, as well as the energetic stability and dispersion phonon of SiGaS monolayer. The results show that using approaches based on the generalized gradient approximation (GGA) and the HSE06 hybrid exchange-correlation functional for the minimum energy optimized structure, a direct bandgap of 1.247 and 2.132 eV was obtained within the GGA-Perdew-Burke-Ernzerhof (GGA-PBE) and HSE06 calculation level, respectively. The optical absorption was sensitive to the plane of polarization of the incident light, especially in the UV-vis regions. Power conversion efficiency (PCE) and Shockley-Queisser minimum limit estimated were approximately 19.46%. Moreover, from calculations of the thermodynamic potentials within the PBE functional, the free energy () indicates that this SiGaS monolayer could potentially be synthesized spontaneously at low temperatures. All properties calculated in this study indicate that the SiGaS monolayer could have potential applications in solar cells. However, only experiments can confirm this.