N-ZnO/n-GaAs Heterostructured white light-emitting diode: Nanoscale interface analysis and electroluminescence studies

Abstract

n-ZnO/n-GaAs heterostructured light-emitting diodes have been fabricated by a low-cost ultrasonic spray pyrolysis technique. Nanoscale interface analysis was carried out with scanning transmission electron microscopy. An ∼8.6-nmthick amorphous GaAsZnInO was found in the n-ZnO/n-GaAs interface. A strong and broad white electroluminescence band centered at ∼525 nm and a weak near-infrared emission peaked at ∼815 nm were observed when n-GaAs was positively biased. The 815-nm emission is believed to be related to the interface layer, and the 525-nm emission is assigned to the recombination of electrons from conduction band to deep-level holes in the ZnO layer. © 2009 IEEE.