Theoretical study of copper nitrides Cu n N (n=1, 3 and 4): insight first-principles calculations

Abstract

ABSTRACT To study the structural, electronic, elastic, thermodynamical and thermoelectric (TE) properties of copper nitride ( with n=1, 3, 4), we have used density functional theory (DFT) based on the generalized gradient approximation and semi-classical Boltzmann transport theory. The band structure and electronic density of states (DOS) confirm that has a semiconductor behavior with an indirect bandgap of 0.32 eV, however, CuN and have metallic behavior. The study of elastic constants and their derived parameters of in cubic structure revealed that the compounds are ductile, mechanically and dynamically stable and have an ionic bond. This study shows that the hardness and thermal stability of increase with n increase from 1 to 4. The TE properties are calculated and found to decrease with n. The calculated values of ZT are 0.975, 0.84 and 0.023 at 300 K, which makes CuN and are good candidates for thermoelectric applications.