Electronic and Thermoelectric Properties of Yb2+-Doped Cubic Perovskite CsCaCl3: A First-Principles Study

First-principles calculations are used to study the structural, electrical, and thermoelectric properties of pure and Yb 2 + -doped CsCaCl 3 perovskite. Thermoelectric transport properties as a function of chemical potentials ( μ ), temperature ( T ), and Yb 2 + dopant concentration ( x ) are computed using semi-classical Boltzmann theory implemented in the BoltzTrap code. The calculated indirect bandgap of pure CsCaCl 3 is 5.35 eV, and it behaves like an insulator. To tailor the electronic and thermoelectric properties of the CsCaCl 3 compound, we considered substitutional doping with the lanthanide Yb 2 + atom for possible desired applications. According to the predicted formation energy, Yb 2 + -doped at the cation site (Ca-site) is structurally more stable than at the anion site. Within the bandgap of pure CsCaCl 3 , the Yb 2 + dopant induces defective states. As a result, transitions from insulator to semiconductor and indirect to direct bandgap occurred. According to the partial density of states, the Yb 2 + atom’s f -orbital produced impurity states above the valance band maximum (VBM), resulting in a narrower bandgap. For both values of chemical potential ( μ = conduction bad minimum [CBM] and VBM), we characterize the thermoelectric properties. Additionally, various Yb 2 + dopant concentrations were taken into account. At μ = CBM, substitutional Yb 2 + doping at a concentration level of 1.67 % demonstrates an improvement in the thermoelectric properties. The highest ZT value for CsCaCl 3 :Yb 2 + 1.67 % at μ = CBM is 1.4 at 1150 K. According to the ZT value, Yb 2 + -doped CsCaCl 3 cubic perovskite compound can be used in thermoelectric applications. Graphical Abstract