Photoluminescence investigations of diffused GaAs light emitting diodes

Abstract

A useful method to investigate depth profiles of the minority carrier lifetime, internal quantum efficiency and doping concentration in zinc diffused GaAs LED's is described. The depth profiles are measured by the photoluminescence technique after subsequent removal of thin layers. At a surface zinc concentration of about 1019 cm−3 the light output power of the LED's, the minority carrier lifetime, and the photoluminescence intensity reach maximum values. From the depth profiles the influence of the reabsorption coefficient and the p‐n junction depths on the light output power is shown. The results are confirmed by electroluminescence measurements.