Effects of high-dose 40MeV proton irradiation on the electroluminescent and electrical performance of InGaN light-emitting diodes

InGaN multi-quantum-well light-emitting diodes (LEDs) in the form of unpackaged die with emission wavelengths from 410 to 525nm were irradiated with 40MeV protons to doses of 5×109–5×1010cm−2. The highest dose is equivalent to more than 100 years in low-earth orbit. The projected range of these protons is >50μm in GaN and thus they traverse the entire active region. The electroluminescent intensity from the LEDs decreased by only 15%–25% even for the highest doses and the reverse breakdown voltage increased by 1–2V from their control values of ∼21–29V. The percentage change in breakdown voltage and electroluminescence intensity was independent of the initial emission wavelength over the range investigated, within experimental error. The GaN LEDs exhibit extremely good stability to these high-energy proton irradiations with no measurable change in contact resistance or contact morphology.