Analysis of the Electronic and Thermoelectric Properties of 2-D HfSe₂ using Density Functional Theory

Thermoelectricity is a rapidly growing research field in physics and energy, as it addresses both current and future energy challenges. Thermoelectric devices can convert heat energy into electrical energy or vice versa, making use of waste heat and contributing to the shift towards renewable energy. A key area of research is the search for new materials that can be used in thermoelectric devices. This study explores the potential of 2D HfSe 2 as a thermoelectric material with density functional theory (DFT) calculations using Quantum ESPRESSO. We also determine the stability of HfSe 2 by plotting the phonon dispersion curves using Phonopy. The results indicate that 2D HfSe 2 exhibits good thermoelectric performance and dynamic stability. With power factor (PF) values for p-type at 300 K, 500 K, 700 K, and 900 K of 0.77 mW/m 2 ·K 2 , 1.20 mW/m 2 ·K 2 , 3.95 mW/m 2 ·K 2 , and 7.06 mW/m 2 ·K 2 , respectively, and for n-type of 0.78 mW/m 2 ·K 2 , 1.20 mW/m 2 ·K 2 , 1.64 mW/m 2 ·K 2 , and 2.00 mW/m 2 ·K 2 , respectively. The ZT values for p-type at 300 K, 500 K, 700 K, and 900 K were 2.2, 1.3, 0.57, and 0.31, while for n-type, the ZT values were 3.3, 1.7, 0.75, and 0.39.