Experimental proof of the existence of the double space charge developed in dielectrics by the Costa Ribeiro effect

Abstract

Experimental proof of the double space charge in dielectrics and organic semiconductors due to the Costa Ribeiro effect is given and the theory of distribution of such charges with two zero‐field planes is tested. This was accomplished by the liberation of charges inside the crystal by means of a focused beam of light that crossed thin layers of the crystal. The produced current changed sign twice when the beam swept over the thickness of the crystal showing the existence of the two zero‐field planes.