Investigation of Thermoelectric and Structural Properties of BeAlH₃, BeGaH₃, and BeInH₃ perovskite Hydrides for Energy Applications

Abstract

This study explores the structural, electrical, and thermoelectric properties of crystalline beryllium hydrides BeXH3 (X = Al, Ga, In) using the generalized gradient approximation (GGA) within the framework of density functional theory (DFT). The analysis is performed using the BoltzTrap package, integrated with the Wien2k code, and the Murnaghan equation of state to determine total energy and atomic volume while providing detailed information on band structure and electronic densities of states. Key thermoelectric properties, including power factor (PF), figure of merit (Zt), thermal conductivity (k), and electrical conductivity (σ), were investigated over a temperature range from 300 to 900 K. The results show that BeGaH3 exhibits the best thermoelectric performance over the entire temperature range, with a maximum electrical conductivity of 3.5*10²⁰ (1/Ω.m) at 900 K. In contrast, BeAlH3 and BeInH3 show interesting thermoelectric behaviors with an increase in efficiency at higher temperatures. Thermal conductivity increases with temperature, influenced by electron vibrations, while Zt and PF factors show material-specific variations, highlighting the optimization potential of these compounds for thermoelectric devices.