Improved long-term thermal stability of InGaN/GaN multiple quantum well light-emitting diodes using TiB2- and Ir-based p-Ohmic contacts.

InGaN/GaN multiple quantum well light-emitting diodes (MQW-LEDs) were fabricated with either Ni/Au/TiB₂/Ti/Au or Ni/Au/Ir/Au p-Ohmic contacts and annealed at 200 and 350 °C for 45 days. By comparison with companion devices with conventional Ni/Au Ohmic contacts fabricated on the same wafer, MQW-LEDs with TiB₂- and Ir-based Ohmic metallization schemes showed superior long-term thermal stability as judged by the change in turn-on voltage, leakage current, and output power, a promising result for applications where reliable operation at high temperature is required. [ABSTRACT FROM AUTHOR]