Advancing photovoltaics and optoelectronics: Exploring the superior performance of lead-free halide perovskites

One of the emerging directions that has greatly advanced the fields of photovoltaics and optoelectronics is the development of lead-free inorganic halide perovskites. In this study, ab-initio methods were employed to forecast the structural, electronic, and optical behavior of the perovskite materials Cs2Cu+Al3+X6 (where X represents Cl or Br). The analyses conducted have revealed the exceptional structural characteristics of these compounds. The electronic band structure and density of states were computed using the PBE method with the mBJ potential. The direct bandgaps of Cs2CuAlCl6 and Cs(2)CuAlBr(6 )were determined to be 1.35 eV and 0.93 eV, respectively. This suitable electrical bandgap results in high visible-light absorption. As a result, the optical characteristics exhibit a significant absorption coefficient (alpha(omega) approximate to 1.1 x 10(5) cm(-1) for Cs2CuAlBr6 and 0.77 x10(5) cm(-1) for Cs2CuAlCl6), substantial conductivity, and negligible reflectivity (R(omega) < 10%). These attributes render Cs(2)CuAlCl(6 )and Cs2CuAlBr6 semiconductors highly appealing for optoelectronic applications. The maximum spectral light conversion efficiency under AM1.5G solar irradiation was assessed by altering the thickness of the structures. The results reveal that the chlorinated perovskite achieves a slightly higher efficiency of 32.72%, whereas the brominated perovskite reaches an efficiency of 29.31%. Despite their remarkably advantageous bandgaps, limited reflectivity, and impressive efficiency, environmentally friendly halide perovskite compounds hold promise as renewable energy conversion materials. This suggests the potential for substantial enhancements in solar cell performance. Furthermore, employing the finite element (FE) method, we performed calculations to assess carrier generation within a specially engineered solar cell structure comprising an environmentally friendly multilayer (CH3NH3SnI3 and Cs2CuAlX6). Our discoveries unveiled an exceptionally elevated total generation rate at the interfaces between CH3NH3SnI3 and Cs2CuAlX6, reaching approximately 2.5 x 10(29) m(-3)/s. These findings offer novel perspectives that contribute to the research community and hold the potential to advance future solar cell systems.