Degradation of green light-emitting GaP:N diodes

Abstract

The degradation is studied of VPE GaP:N LEDs with various stress currents. The degradation is monitored during stressing by periodically measuring the optical flux as a function of the current and the I—U characteristic. Several additional measurements are made in dependence on the degradation. These include spectral electroluminescence (300 and 77 K), minority carrier lifetime, diffusion lengths of the minority carriers, and the optical material efficiency. In the process of degradation the high material efficiency of the p‐region compensates the strong decrease of the efficiency in the n‐region by increasing the injection of electrons into p‐region.