The effect of high intensity of electric fields on the operation of a single-crystal Si solar cell was investigated in this work. A single-crystal Si solar cell was irradiated by spontaneous and stimulated light sources. Firstly, a triac-lamp having a tungsten filament and green, yellow, red and blue LEDs from the spontaneous light sources were used to irradiate the solar cell exposed to a high-intensity electric field E-DC. Later, as a stimulated light source He-Ne laser with; lambda = 633.8 nm and P = 1 mW was utilized, and the behaviour of the solar cell exposed to the electric field E-DC ranging from 100 x 10(3) to 500 x 10(3) V/m was studied. The results showed that the V-oc value of the solar cell irradiated by the two light sources mentioned above decreased due to the electric field. (c) 2005 Elsevier B.V. All rights reserved.