Degradation of electrooptical characteristics of serial GaP light-emitting diodes, caused by fast electrons

Abstract

The study of electrical and optical characteristics of GaP LEDs irradiated with electrons (E = 2 MeV, Ф = 0…10¹⁵ cm⁻²) was performed. Especial interest was focused on appearing of S-type instability in current-voltage characteristics and its mechanism in accord with the model by K. Maeda. Made in this work was the analysis of changes in the concentration of deep recombination levels caused be irradiation. The coefficient of radiation damages of charge carrier lifetime in GaP was estimated (kτ = 1.5·10⁷7 s·cm⁻²). It was discovered that the luminescence intensity recovering after isochronous annealing possesses two stages. Heating the diodes up to T > 350 °C leads to destruction of p-region in the diode and deterioration of lens optical transmission.