Abstract
ZnO heterojunction light emitting diodes (LEDs) were passivated by plasma-enhanced chemical vapor-deposited SiO 2 and SiN X . Post-dielectric deposition annealing was critical in obtaining good LED electrical and optical characteristics. No diode characteristics or light emission were observed unless the structures were annealed at 350°C after fabrication. Annealed diodes showed band-edge electroluminescence (385 nm) and a broad defect band with a peak at 930 nm at room temperature. The SiO 2 and SiN x had very different passivation effects in terms of the electrical and electro-luminescence characteristics of the LEDs. After annealing, the SiO 2 passivated ZnO LEDs showed diode IV characteristics and emitted light. However, the annealed SiNkpassivated ZnO LEDs showed leaky diode characteristics and no light emission. We attnbute these differences to the role of hydrogen on the LEDs. © The Electrochemacal Society.