Electroluminescence from annealed ZnO nanowires

We report the effect of thermal annealing on the room-temperature electroluminescence in vertically oriented ZnO nanowires. Ultra-violet luminescence around 390 nm and a broad defect-related band centered at 620 nm are observed. The ZnO nanowires are grown in electrodeposition on SnO2-coated glass substrates, employing a technique that is suitable for large-area applications. The nanowires are robustly encapsulated in thin polymer films deposited from low-viscosity solutions. Electron injection occurs through a transparent SnO2layer, while hole injection is mediated by a p-doped polymer layer and an evaporated Au-contact.