Photosensitive semiconductor device employing induced space charge generated by photosensor

Claim 1

A PHOTOSENSITIVE SEMICONDUCTOR DEVICE COMPRISING A SEMICONDUCTOR BODY, SPACED CONTACTS TO THE SEMICONDUCTOR BODY, MEANS FOR APPLYING A VOLTAGE ACROSS THE CONTACTS TO ESTABLISH IN THE BODY IN A DIRECTION SUBSTANTIALLY PARALLEL TO A SURFACE OF THE BODY IN A DIRECTION SUBSTANTIALLY FLOW OF CURRENT THERETHROUGH, A BODY OF PHOTOSENSITIVE MATERIAL LOCATED ADJACENT THE SAID SURFACE OF THE BODY AND SEPARATED THEREFROM BY A BLOCKING LAYER, SAID BODY OF PHOTOSENSITIVE MATERIAL HAVING A HIGH DARK SHEET RESISTANCE AND A THICKNESS AT WHICH, AT LEAST IN THE PHOTOSENSITIVE MATERIAL PORTION ADJACENT THE JUNCTION AND SUBSTANTIALLY PARALLEL THERETO, THERE APPEARS A POTENTIAL GRADIENT CORRESPONDING TO THAT WHICH EXISTS IN THE SEMICONDUCTOR BODY WHEN THE VOLTAGE IS APPLIED, MEANS FOR IRRADIATING THE PHOTOSENSITIVE BODY WITH RADIATION WHICH INCREASE ITS CONDUCTIVITY WITHOUT DIRECTLY VARYING THE CONDUCTIVITY OF THE SEMICONDUCTOR CAUSING A REDUCTION IN THE POTENTIAL GRADIENT IN THE PHOTOSENSITIVE BODY PRODUCING BY CAPACITIVE ACTION AN INCREASED SPACE CHARGE IN THE SEMICONDUCTOR BODY WHICH DECREASES THE CURRENT THEREIN, AND MEANS CONNECTED TO THE SEMICONDUCTOR CONTACTS FOR UTILIZING THE DECREASE IN CURRENT THROUGH THE SEMICONDUCTOR BODY.