Abstract: We have studied the role of EL2 centers in formation of the photoelectric response of an array of radial n-type GaAs/Al_xGa_{1 – x}As (x = 0.3) nanowires (NWs) grown by molecular beam epitaxy on a p-type silicon substrate. Results revealed a significant decrease in the time of NW photoresponse recovery as compared to that in a bulk crystal upon the transition of EL2 centers from a metastable nonactive state to the normal ground state.