Electronic and structural properties of the surfaces and interfaces of indium oxide

摘要

Indium sesquioxide is a transparent conducting oxide material widely used in solar cell and solid-state lighting devices. Following our recent successes in modeling the electronic and defect properties of In_(2)O_(3), we report an investigation of the surface physics of this material. In the ground-state bixbyite phase, the surface energies follow the order (100) > (110) > (111), with the charge neutral (111) termination being the lowest energy cleavage plane; the same ordering preferences have been established for materials adopting the parent fluorite (AB_(2)) structure. Our first-principles predictions, based on density functional theory, are confirmed through collaboration with the group of Russell Egdell at Oxford University, who grew epitaxial In_(2)O_(3) single crystals on lattice matched (100), (110) and (111) Y-stabilized zirconia substrates, and observed that (111) facets spontaneously form on other low index terminations. Furthermore, we have performed work function analysis of the low index In_(2)O_(3) surfaces using a hybrid density functional, which is found to be in very good agreement with recent experiments.