Hybrid DFT studies of bonding, electronic, and thermoelectric properties of LaX3 (X = Pb, In, and Tl) compounds
摘要
This research uses the hybrid functional in the framework of density functional theory (DFT) to study the bonding, electrical, and thermoelectric aspects of LaPb3, LaTl3, and LaIn3 materials. Since these compounds feature 4f orbitals, a substantial electron–electron correlation effect is anticipated. As a result, the Becke, 3-parameter Perdew–-Wang 1991 correlation functional (B3PW91) hybrid functional is also used to determine the electronic characteristics, and its impact on the density of states (DOS) is thoroughly examined. These compounds’ metallic character is shown by their density of states and band structure. In contrast to p-type doping, n-type doping results in greater values for the Seebeck coefficient, thermal conductivities, and electrical conductivities for all materials. The materials’ moderate figure of merit values show that they can be used in situations where low thermoelectric efficiency values are needed and larger values might damage the process, but more experimental confirmation is needed. For the compounds under study, the n-type area exhibits a considerable response of thermal conductivity per relaxation time (κ/τ) in comparison to the p-type region, the peak value for LaPb3, LaTl3, and LaIn3 in n-type region are 3.415 × 1015 Wm−1 K−1 s−1, 1.225 × 1015 Wm−1 K−1 s−1 and 5.565 × 1015 Wm−1 K−1 s−1, respectively, and in p-type are 2.973 × 1015 Wm−1 K−1 s−1, 8.11 × 1014 Wm−1 K−1 s−1 and 5.119 × 1015 Wm−1 K−1 s−1, respectively.