Degradation of Yellow Light-Emitting GaAs0.1P0.9:N Diodes. 1. Implanted Diodes

Abstract

The degradation process is studied on VPE GaAs0.1P0.9: N LED's prepared by Zn implantation for varying forward and stress current during stress time up to 1000 h. Using the scanning electron microscope the diffusion lengths of minority carriers, the doping profile, and the relative internal efficiencies of the p‐ and n‐regions are obtained for different stress stages. The spectra and the decay of injection luminescence are measured as function of the forward current. The decrease of the diode light output is affected by the degradation of the p‐ and n‐regions caused by REDR‐processes. The defect‐reaction induced changes of the doping profiles surrounding the p‐n junction shift the carrier injection ratio to an increasing amount of electron injection into the more efficient p‐region.