His research interests lie in novel electronic materials, including wide-band-gap semiconductors (III-V nitrides, II-VI compounds), transparent conductors, and complex oxides; loss mechanisms in light emitters; two-dimensional conductors; quantum information science; and physics and chemistry of hydrogen interactions with solids. First-principles computational techniques are used to study atomic and electronic structure of crystalline, polycrystalline and amorphous materials; interfaces, surfaces, and defects; and heterojunctions and superlattices.