Surface controlled field effect solid state device

Abstract

An electronic solid state device comprising an inhomogeneous body in which grains of semiconductor material are present. The contact between adjoining grains is such that in the interface regions there is continuity between the bulk material of the adjoining grains and the dominant current conduction paths in the body lie within the grains via said grain to grain contacts. At the surfaces of the grains adjoining said interface regions rectifying barrier forming means are provided to enable control of the said current paths by surface field effect depletion in the interface regions. Said means can be opposite conductivity type surface layers at or on the grains. In other devices said means are formed by adsorbed gas atoms, ions or molecules. The said control may be employed to yield photoconductive layers with controllable gain and speed of response, said layers being used, for example, in solid state imaging devices.