First-principles quantum analysis of structural, optoelectronic, and thermophysical properties of Co/Ni doped ceria Ce_1−xTm_xO₂ (Tm=Co, Ni) for solar cell applications

Abstract

The properties of CeO2 thin films, such as their memory store capabilities, visual transparency, chemical and thermal durability, adjustable energy band topologies, and high oxygen storage capacity have captured the attention of scientists. The energy band dispersions for Ce1-xTmxO2 (Tm= Co, Ni; x= 12.5%) are calculated to get insight into the characteristics of the materials under investigation. The anticipated energy bandgaps for Ce1-xCoxO2 and Ce1-xNixO2 are 2.6 and 2.7 eV, respectively, in the spin ↑ channel . However, both compounds show metallic character in in spin ↓ channel. The phenomena of photon absorption/dispersion by the host materials can be elucidated using dielectric function ε(ω) of Ce1-xTmxO2 (Tm= Co, Ni; x= 12.5%). Significant photon absorption can be noted in UV and IR regions for Ce1-xTmxO2 (Tm= Co, Ni; x= 12.5%) in spin ↑ and spin ↓ channels, respectively. Ce1-xTmxO2 (Tm= Co, Ni; x= 12.5%) exhibits a minimal photon reflection, approximately 15%. Ce1-xNixO2 shows excellent thermoelectric characteristics as its ZT value is high (1.8 at 1000K) compared to Ce1-xCoxO2. Based on their thermodynamic properties, Ce1-xTmxO2 (Tm= Co, Ni; x= 12.5%) are thermodynamically stable compounds.