Significant improvement of green light emission efficiency of InGaN/GaN quantum wells by depositing oxide thin films and ultraviolet light irradiations

Abstract

Abstract Light-emitting diodes (LEDs) using InGaN/GaN quantum wells (QWs) have low emission efficiencies in the green wavelength region, a problem known as the “green gap”. Surface plasmon (SP)-enhanced LEDs have attracted considerable attention because of their ability to solve the green gap by improving the internal quantum efficiency (IQE). However, there is no suitable metal for enhancing green light emissions using the propagating mode of SP resonance with thin metal films. Additionally, other problems, such as large absorption loss because of metals and difficulty in extracting light from the SP resonance modes, have prevented practical application of SP-enhanced LEDs. Herein, we propose a novel method to improve the IQE of green-light-emitting InGaN by depositing oxide thin films instead of metals and ultraviolet (UV) light irradiation. The innovativeness of the proposed method solves the problems of emission enhancements using plasmonics with metals, making it suitable for developing high-efficiency LED devices for practical applications.