Optical measurements and Burstein Moss effect in optical properties of Nb-doped BaSnO3 perovskite

Abstract

The research for novel transparent electrodes has gained popularity due to the low abundance and the high cost of Indium. In this paper, we used first-principles calculations employing density functional theory with the exchange-correlation energy functional approximation Generalized Gradient Approximation to analyze the optical, structural, and electronic properties of Niobium doped Barium tin oxide with 12.5%, 6.25%, and 3.125% of doping. The electronic structure calculations show an indirect bandgap of Barium tin oxide. Niobium induces extrinsic donor energy states around the bottom of the conduction band giving rise to an improvement in the electrical conductivity in the system. The Fermi level shifts upward to the conduction band, a typical characteristic of an n-type semiconductor. Burstein Moss effect was found in the optical measurements for the dope systems, leading to an increase in the apparent bandgap. A diminution in the absorption coefficient in the UV–visible range of the light was presented. These characteristics suggest that Nb-doped BaSnO3 is a promising transparent conducting oxide and can be useful for optoelectronic applications.