Electronic and Thermoelectric Properties of n- and p-type Cubic and Tetragonal Cu3VSe4 Crystal Structure, A First Principle Stud

Abstract

In this study, we have investigated the properties of Cu3VSe4, a sulvanite material, in both its cubic and tetragonal phases by implementing first-principles computations founded on density functional theory. Our calculations reveal that the cubic phase's lattice parameters are a = b = c = 5.62 Å, while the tetragonal phase has lattice parameters are a = b = 5.77 Å and c/a = 1.032, which corresponds to c = 5.95 Å. Both phases are found to be thermodynamically stable and non-magnetic in their intrinsic form. The band gaps of the cubic and tetragonal phases are 0.91 eV (M-X) and 0.62 eV (R-X), respectively, and both are indirect in nature. We have also studied the total density of states (DOS) in company with, the partial density of states (PDOS) of both phases, and figure 4.6 provides a detailed insight into the nature of the compound. Moreover, we have used the semi-local Boltzmann transport theory to derive various thermoelectric properties of the two phases of Cu3VSe4 at different temperatures, including the Seebeck coefficient (S), conductivity (σ), power factor (PF), electronic thermal conductivity (кe), and figure of merit (ZT), as mentioned in equation 1.6. Our results indicate that the cubic phase of Cu3VSe4 has a ZT value of 0.716 for n-type at a temperature range of 750-900 K and 0.67 for p-type at 1200 K. On the other hand, the tetragonal phase exhibits a ZT value of 0.959 for n-type at 857 K and 0.788 for p-type xxii at 900 K. These ZT values demonstrate that both phases of Cu3VSe4 are highly suitable for thermoelectric applications. In addition, the effects of strain (ε=0, ±5, ±10) on the cubic phase are are quite astonishing as with the increase or decrease in strain electronic properties i.e band gap values of cubic Cu3VSe4, also increase or decrease. The variation in the electronic properties also influence the thermoelectric properties of this phase. In summary, our analysis provides valuable insights into the properties of Cu3VSe4 in both its cubic and tetragonal phases and highlights the potential of this material for thermoelectric applications.