Optoelectronic and Thermal Properties of BaZrS_3−xSe_x Perovskites for Solar Absorber Materials

This study investigates BaZrS (3−x) Se (x) alloys for solar cells, using DFT to analyze their structural, mechanical, Dynamical, electronic, optical, and thermal properties. It’s the first exploration of mechanical and thermal aspects, crucial for material stability. The barium-derived perovskite chalcogenide was analyzed via Wien2k code and FP-LAPW method, with GGA-PBE and mBJ approaches. Chalcogenides are promising semiconductors due to thermal stability and non-toxicity. The research focuses on substituting sulfur with selenium in BaZrS (3−x) Se (x) . Lattice parameters align with data. Equilibrium volume increases with selenium, while the bulk modulus decreases from BaZrS 3 to BaZrSe 3 . The energy band gap initially decreases with the addition of Se, reaching a minimum at BaZrSSe 2 , before slightly increasing again at BaZrSe 3 . Optically, Se incorporation shifts UV absorption into the visible spectrum, with BaZrSe 3 showing broad absorption and high coefficients. Under pressure, volume increases with temperature but decreases with pressure, while the bulk modulus changes oppositely. Heat capacity and thermal expansion increase with temperature. BaZrS (3−x) Se (x) perovskites show mechanical stability and ductility, suitable for solar cells, thus advancing high-efficiency photovoltaic devices.