Insights into structural, Electronic and Thermoelectric properties of ZnTMN2 (TM= Zr and Hf): A First-Principles study

Abstract

We employ first-principles calculations combined with semi classical Boltzmann transport theory to investigate the structural, electronic, and thermoelectric properties of ZnTMN₂ (TM= Zr and Hf). The negative value of formation energy confirms the stability of these compounds. We used Tran Blaha modified Becke Johnson approximation to calculate electronic properties. ZnZrN₂ and ZnHfN₂ are having indirect bands of magnitude 2.77 eV and 3.31 eV, respectively. The positive value of the Seebeck Coefficient at all studied temperatures confirms its p-type nature. The thermal conductivity slightly decreases with a rise in temperature in ZnHfN₂ as compared to ZnZrN₂. The observed value of the figure of merit is 0.80 and 0.81 at 500 K and 600 K for ZnZrN₂ and ZnHfN₂, respectively. The high figure of merit of Hf and Zr-based nitrides make them a potential material for thermoelectric energy harvesting applications.