Ultraviolet light emitting diode with n-ZnO:Ga/i-ZnO/p-GaN:Mg heterojunction

Abstract: n-ZnO:Ga/p-GaN:Mg heterojunction light emitting diodes (LEDs) were fabricated at different growth temperatures and carrier concentrations in the n-type region. The effects of growth temperature and carrier concentration on the electrical and emission properties were investigated. The I–V and EL results showed that the improved device performances such as lower turn-on voltage and true ultraviolet emission were achieved with the insertion of a thin intrinsic layer between n-ZnO:Ga and p-GaN:Mg. This observation was attributed to a lowering of energy barriers for the supply of electrons and holes into intrinsic ZnO and recombination in the intrinsic ZnO with the absence of deep-level emission. [Copyright &y& Elsevier]