First-principles quantum analysis of structural, optoelectronic, and thermophysical properties of Co/Ni doped ceria Ce<sub>1−x</sub>Tm<sub>x</sub>O<sub>2</sub> (Tm=Co, Ni) for solar cell applications
Shafaat Hussain Mirza, Zeesham Abbas, Amna Parveen, Shoyebmohamad F. Shaikh
Abstract
Abstract The properties of CeO 2 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 Ce 1−x Tm x O 2 (Tm = Co, Ni; x = 12.5%) are calculated to get insight into the characteristics of the materials under investigation. The anticipated energy bandgaps for Ce 1−x Co x O 2 and Ce 1−x Ni x O 2 are 2.6 and 2.7 eV, respectively, in the spin ↑ channel. However, both compounds show metallic character in inspin ↓ channel. The phenomena of photon absorption/dispersion by the host materials can be elucidated using dielectric function <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>ε</mml:mi> <mml:mrow> <mml:mfenced close=")" open="(" separators=""> <mml:mrow> <mml:mi>ω</mml:mi> </mml:mrow> </mml:mfenced> </mml:mrow> </mml:math> of Ce 1−x Tm x O 2 (Tm = Co, Ni; x = 12.5%). Significant photon absorption can be noted in UV and IR regions for Ce 1−x Tm x O 2 (Tm = Co, Ni; x = 12.5%) in spin ↑ and spin ↓ channels, respectively. Ce 1−x Tm x O 2 (Tm = Co, Ni; x = 12.5%) exhibits a minimal photon reflection, approximately 15%. Ce 1−x Ni x O 2 shows excellent thermoelectric characteristics as its ZT value is high (1.8 at 1000K) compared to Ce 1−x Co x O 2 . Based on their thermodynamic properties, Ce 1−x Tm x O 2 (Tm = Co, Ni; x = 12.5%) are thermodynamically stable compounds.