Unveiling the DFT perspectives on structural, elastic, optoelectronic, and thermoelectric properties of zirconate perovskites XZrO3 (X = Ca, Sr, Ba)

Abstract

A thorough comparative study of lead free zirconate perovskite XZrO3 (X = Ca, Sr, Ba) is carried out employing WIEN2k which is a density functional theory based code. A good agreement between reported synthesis and the theoretical results is observed. BaZrO3 can be inferred as the most stable compound among XZrO3 (X = Ca, Sr, Ba) as its ground state energy is lowest. According to the Burn-Haun criterion, the compounds under research are mechanically stable. The ductile nature, anisotropy, and reasonable resistance to deformation in response to external stress are observed. The semiconducting nature of the compounds is observed having indirect band gaps with values of 3.25 eV, 3.71 eV, and 3.80 eV. Exceptional optical absorption peaks for the investigated compounds can be observed in UV region (around 5.0 eV) which suggests their numerous optoelectronic applications within UV. XZrO3 (X = Ca, Sr, Ba) are active optical materials as their refractive inrdex n(omega) occurs in the range of 1.0 and 2.0. Thermoelectric properties of these compounds are also very promising since the large Seebeck coefficients (similar to 2250-2700 mu V/K), large power factor values (similar to 10(11) W/mK(2)s), and figure of merits are very close to the unity are observed. The mechanical stability and ductility, and the appealing optical and thermoelectric properties of the examined compounds persuade us that these compounds may play a significant role for numerous industrial applications like solar cells, LEDs, sensors, thermoelectric generators and other energy conversion devices in the future.