Saturated blue-violet electroluminescence from single ZnO micro/nanowire and p-GaN film hybrid light-emitting diodes

Abstract

Saturated electroluminescence behavior was observed in single ZnO micro/nanowire and GaN film heterojunctions fabricated by transferring an individual ZnO micro/nanowire onto p-type GaN substrate. A strong blue emission of ∼460 nm was observed, as a result of interfacial radiative recombination of electrons from n-ZnO and holes from p-GaN. Light-output-current characteristic followed a power law of L ∼ Im, which revealed a superlinear dependence at low current (m = 1.16) and became sublinear (m = 0.72) at high current. According to theoretical analysis, the saturated electroluminescence at high current could be attributed to the saturation of nonradiative recombination and the limitation of electrical-to-optical conversion efficiency.