The homo-transitional original and irradiated by electrons with E = 2 MeV; F = 5.9⋅1014 cm-2 ÷ 8.2⋅1016 cm-2 GaP LEDs were studied. The effect of radiation treatment on their electrical and optical characteristics was studied; the results of isochronous annealing of irradiated samples are given; the consequences of high-temperature annealing of output diodes are analyzed. Peculiarities of the formation of the current-voltage characteristics of red LEDs doped with Zn, O, and green LEDs doped with N under reverse bias, as well as features of the recovery of the reverse current during annealing of both types of LEDs, are revealed.