Tuning The Electronic Structure Of D(0) Perovskite Oxides By Combining Distortive Modes

Transition metal oxides in the d(0) perovskite class, defined broadly to include WO3, have shown promise as light absorbers for photocatalytic applications. These compounds are highly tunable in their composition and atomic structure, and consequently, in their electronic structure and properties. Through the lens of atomic orbital interactions and density functional theory calculations, the present work explores how and why certain structural distortions tune the band gaps and band edges of WO3 and d(0) perovskite oxides. It is determined that, because an individual distortive mode (e.g., polar distortion along or octahedral rotation around a cubic perovskite axis) changes the character of only some band-edge orbitals, combinations of distortive modes may tune band gaps much more significantly than the sum of individual modes. The implications of this tunability are discussed for WO3 as a photocatalyst, and for d(0) perovskite oxides more generally.