Modelling of proton irradiated GaN-based high-power white light-emitting diodes

We report the effects of high-energy (23 GeV) proton irradiation at large fluences on packaged high-power GaN-based white light-emitting diodes with YAG:Ce phosphors. From optical and electrical measurements, we assume that proton irradiation degrades only the GaN LED die up to fluences of at least $2 \times 10^{14}$p/cm$^{2}$, and we demonstrate that it produces nonradiative recombination centres which increase the leakage current and diminish the carrier density in the quantum wells and hence the output optical power. We also propose for the first time a model correlating optical and electrical degradation induced by radiation.