Affiliation:
1. Nanjing University
2. Nanjing University of Posts and Telecommunications
3. Xiamen University
Abstract
We proposed a “Ni sacrifice” method to fabricate Al-based highly reflective p-electrode in the ultraviolet spectral region for AlGaN-based deep-ultraviolet light-emitting diodes (DUV-LEDs). The “Ni sacrifice” p-electrode could have a high optical reflectivity of around 90% at the DUV spectral region below 300 nm. Compared to Ni/Au, indium tin oxide (ITO), and Pd p-contacts, the “Ni sacrifice” led to a higher resistivity of p-contacts and a slightly higher operated voltage of the DUV-LEDs (within 0.6 V at 20 mA). Although the electrical performance was degraded slightly, the light output power and external quantum efficiency of the DUV-LEDs could be improved by utilizing the “Ni sacrifice” p-electrode. Besides, we introduced a grid of vias in the device mesa and reduced the diameter of the vias to achieve an enhanced peak external quantum efficiency (EQE) up to 1.73%. And the wall-plug efficiency (WPE) of DUV-LEDs with a “Ni sacrifice” p-electrode was higher than that of Ni/Au p-electrode DUV-LEDs at low currents. These results highlight the great potential of the proposed “Ni sacrifice” reflective p-electrode for use in DUV-LEDs.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Natural Science Foundation of Jiangsu Province
The Science Foundation of Jiangsu Province
Fundamental Research Funds for the Central Universities
Subject
Atomic and Molecular Physics, and Optics