A first-principles investigation on electronic, optical and thermoelectric properties of $\hbox {La}_{2}\hbox {Pd}_{2}\hbox {O}_{5}$ compound

Abstract

A number of ternary-semiconductor oxides have shown promise for potential applications in catalysis, thermoelectricity, optoelectronics and electrochemistry. In this work, the thermoelectric and optoelectronic properties of $\hbox {La}_{2}\hbox {Pd}_{2}\hbox {O}_{5}$ compound are studied by the full-potential linearized augmented plane wave method based on density functional theory. The electronic band structure shows an indirect band gap of 1.342 eV for $\hbox {La}_{2}\hbox {Pd}_{2}\hbox {O}_{5}$. Partial and total density of states indicate strong hybridization among different electronic orbitals. The upper part of the valence band is dominated by the Pd-d and O-p states, while the lower conduction band originates mainly from the Pd-d state. Dielectric functions including the imaginary and real parts, along with other optical constants, such as absorption coefficient, energy loss function, reflectivity and refractive index, have been reported for the first time. Thermoelectric properties, including electrical and thermal conductivity, Seebeck coefficient and power factor with variation in temperature are also presented and discussed using semi-classical Boltzmann transport theory for the first time for $\hbox {La}_{2}\hbox {Pd}_{2}\hbox {O}_{5}$. It has been found that $\hbox {La}_{2}\hbox {Pd}_{2}\hbox {O}_{5}$ has attractive optoelectronic and thermal properties that can make it a suitable candidate for efficient thermoelectric and optoelectronic device applications.