Hybrid functional density functional theory calculations of the oxygen vacancy (VO) in monoclinic bulk WO(3) provide a coherent rationalization for the strong dependence of WO(3-x) electronic properties on the VO concentration and of the semiconductor-to-metal transition, a phenomenon intimately connected to the electrochromic effect. Different VO centers containing W(4+), W(5+), and W(6+) species are expected to coexist. Optical transition levels are 0.7-1.0 eV below the conduction band minimum, in agreement with experiments. The complex nature of V(O) in WO(3) can only be detected with methods that properly describe band gaps and polaronic distortions at defect sites.
Wang, F., DI VALENTIN, C., Pacchioni, G. (2011). Semiconductor-to-metal transition in WO(3-x): Nature of the oxygen vacancy. PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS, 84(7), 073103 [10.1103/PhysRevB.84.073103].
Semiconductor-to-metal transition in WO(3-x): Nature of the oxygen vacancy
DI VALENTIN, CRISTIANA;PACCHIONI, GIANFRANCO
2011
Abstract
Hybrid functional density functional theory calculations of the oxygen vacancy (VO) in monoclinic bulk WO(3) provide a coherent rationalization for the strong dependence of WO(3-x) electronic properties on the VO concentration and of the semiconductor-to-metal transition, a phenomenon intimately connected to the electrochromic effect. Different VO centers containing W(4+), W(5+), and W(6+) species are expected to coexist. Optical transition levels are 0.7-1.0 eV below the conduction band minimum, in agreement with experiments. The complex nature of V(O) in WO(3) can only be detected with methods that properly describe band gaps and polaronic distortions at defect sites.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.