Insight in the properties of WO3|Y: A first-principle study

Abstract

In this paper, the properties of WO3|Y when yttrium atoms are adsorbed on the surface of WO3 are studied systematically using first-principles calculations. The most stable WO3(0 0 1) surface configuration (W-O terminal surface) was obtained by calculating the surface energy of the clean surface model. By calculating the adsorption energy (Eads), the most stable adsorption site (S1) was obtained, which has the most negative adsorption energy (−5.58 eV). When one yttrium atom is adsorbed on the most stable adsorption site, the work function (Ф) of the system is reduced from 4.26 to 3.26 eV. The WO3(0 0 1) is found to be an n-type semiconductor with a Fermi level of −0.77 eV by analyzing the energy band structure and density of states. When one Y atom is adsorbed at the S1 site, the Fermi level rises to 0.20 eV, and the band gap width is reduced from 0.33 to 0.14 eV. This finding indicates that WO3(0 0 1) is still an n-type semiconductor, but with a considerably increased absorption range of light. Keywords: WO3, Yttrium, Surface adsorption, Work function, First-principle calculation, Adsorption energy