Exploring the Physical Properties of Cu <sub>2</sub> WSe <sub>4</sub> for Optoelectronic and Thermoelectric Applications: A DFT Study
M. Nadeem, Moeen Ud Din, Haider T. Naeem, Qurat Ul Ain, Junaid Munir
Abstract
Full-potential linearized augmented-plane wave method and Boltzmann transport theory are used to study the electrical, thermoelectric and optoelectronic response of the Cu 2 WSe 4 compound. The calculations are performed with the Perdew–Burke–Ernzerhof generalized gradient approximation (PBE-GGA) and modified Becke–Johnson (mBJ) potential. Structural optimization and formation energy calculations justify the stability of the studied compound. An indirect bandgap (N-Γ) of 1.36 eV with GGA and 1.52 eV with mBJ is achieved. The density of states also exposes the bandgap and confirms the semiconducting nature of Cu 2 WSe 4 . The optical properties such as dielectric function, refractive index, absorption coefficient and energy loss are also calculated. The thermoelectric response is calculated through the figure of merit (ZT), Seebeck coefficient, electrical and thermal conductivity and power factor. At high temperatures, a moderate ZT value of 0.65 is achieved with mBJ potential, which shows the possibility to use Cu 2 WSe 4 in the renewable energy device.