Doping and Anisotropy–Dependent Electronic Transport in Chalcogenide Perovskite CaZrSe3 for High Thermoelectric Efficiency

Abstract

AbstractThe potential of an environmentally friendly and emerging chalcogenide perovskite CaZrSe3 for thermoelectric applications is examined. The orthorhombic phase of CaZrSe3 has an optimum band gap (1.35–1.40 eV) for single‐junction photovoltaic applications. The predictions reveal that CaZrSe3 possesses an absorption coefficient of ≈4 × 105 cm−1 at photon energies of 2.5 eV with an early onset of optical absorption (≈0.2 eV) well below the optimum band gap. Seebeck coefficient, S, is inversely proportional to the carrier mobility as the calculated average effective mass for electrons is higher than for holes; p‐type doping enhances the electrical conductivity, σ. The electronic thermal conductivity κe remains low at all temperatures. The upper limit of the thermoelectric figure of merit (ZTe) attains ≈1.0 when doped at specific chemical potentials, while a high Seebeck coefficient contributes to the ZTe = 1.95 at 50 K for p‐type doping with 1018 cm−3 carrier concentration, demonstrating high thermoelectric efficiency.