Investigating the effect of oxygen vacancy on electronic, optical, thermoelectric and thermodynamic properties of CeO<sub>2</sub> (ceria) for energy and ReRAM applications: A first-principles quantum analysis
Shafaat Hussain Mirza, Sikander Azam, Zeesham Abbas, Shoyebmohamad F. Shaikh
Abstract
CeO 2 thin film-based devices have become hot favorite candidates for researchers due to the outstanding characteristics of ceria such as memory storage materials, high oxygen storage capacity, excellent chemical and thermal stability, high transparency in visible region and highly tunable energy band structures. Developing suitable materials for industrial uses like optoelectronic and thermoelectric devices is the primary goal of researchers in the field of renewable energy. Herein, we have investigated the optical, thermoelectric and thermodynamic properties of CeO 2 and [Formula: see text] as promising candidates for energy applications using first-principles calculations. We can observe significant absorption of incident photons by CeO 2 and [Formula: see text] near UV region. The highest peaks of the [Formula: see text] are present around 3.7[Formula: see text]eV in spin [Formula: see text] channel, however, in spin [Formula: see text] channel, the highest peaks of the [Formula: see text] are present around 3.5[Formula: see text]eV. The most intense peaks that emerge are due to the transitions of O[[Formula: see text]] to Ce [[Formula: see text]]. The investigated values of [Formula: see text] reveal that CeO 2 and [Formula: see text] are active optical materials. CeO 2 and [Formula: see text] reflect a negligible number of incident photons ([Formula: see text]%) in the entire energy range. The positive value of the S shows that the CeO 2 under study is p-type semiconductor, while [Formula: see text] is n-type semiconductor as its S value is negative. The S values for CeO 2 are close to the established standard. As a result, CeO 2 is a viable thermoelectric material for use in devices. The figure of merit (ZT) spectra reveals that CeO 2 ([Formula: see text]) is a more capable candidate for thermoelectric materials compared to [Formula: see text] ([Formula: see text]). The investigated thermodynamic parameters reveal that CeO 2 and [Formula: see text] are dynamically stable compounds.