First-principles prediction of mechanical, electronic, optical, and thermoelectric properties of Th3P4 for advanced functional applications

A detailed study of the fundamental principles of Th₃P₄ was carried out using DFT with GGA-PBE and mBJ potentials in order to evaluate its thermoelectric potential. The electronic band structure confirms a clear semiconductor nature with well-defined band gaps, allowing for efficient charge carrier transport. The material exhibits a high Seebeck coefficient of 210 μV/K at 300 K, indicating dominant p-type conduction and a strong thermoelectric response. Temperature-dependent analyses show an increase in electrical and thermal conductivities, which corresponds to the behavior of a p-type semiconductor. The dimensionless figure of merit (ZT) increases monotonically with temperature, reaching 0.74 at 600 K, demonstrating promising thermoelectric efficiency under high-temperature conditions. Additional calculations of the electronic specific heat and Pauli paramagnetic susceptibility confirm the thermal and electronic stability of the material. Overall, these results make Th₃P₄ a strong candidate for high-performance thermoelectric energy conversion systems operating at high temperatures.