450 nm gallium nitride alternating current light-emitting diode

Abstract

Gallium Nitride (GaN) based light-emitting diodes (LEDs) are being utilized in an ever expanding number of applications. The persistent issues, however, have been the use of alternating current (AC) to direct current (DC) converters and the inefficient p-type doping compared to n-type doping. Here, a novel hybrid AC InGaN quantum well (QW) LED without a p-GaN layer is demonstrated at 450 nm. A tunneling LED is fabricated through use of InGaN QWs, combined with a thin Al2O3 dielectric with NiO as the source of the holes. This hybrid InGaN LED utilizes Fowler-Nordheim tunneling and band bending in order to inject holes into the active region. Due to the symmetric nature of the tunneling, hole or electron injection through the top oxide layer leads to AC performance. Room temperature and cryogenic I-V measurements are performed to evaluate the tunneling mechanism. Tunneling of holes is found to lead to earlier device turn-on of ∼0.5 V compared with conventional blue LEDs at ∼2 V. The presented work can lead to a number of novel applications such as on-chip communication, monolithic integration with transistors, and LiFi.