Simplified cell for video retina - using photoconducting element in hydrogenated amorphous silicon carbide

摘要

The photoconducting element contains a layer of photoconducting material (23,35) in this case hydrogenated amorphous silicon carbide joined to two metallic contacts forming electrodes (25,27,33,37) at least one of which is transparent. The mixture of hydrogenated amorphous silicon carbide contains 5-20% carbon. This element is used in the cell of a video retina which contains a field effect transistor possessing a source (12), a drain (12') deposited on an insulating substrate (10) and a canal (16) of a thin semi-conducting layer mounted on an insulating layer (20). This is covered with a metallic grid (24) and also includes a capacitor and a photoconducting element. The capacitor - photoconducting element is formed by the transparent metallic layer above forming the electrode (33) being deposited on the insulating substrate (10) and joined to the source (12) or drain (12') of the transistor which is surrounded by an insulating layer (28) onto which is deposited the photoconducting material (35) which is then covered by a metallic layer (37) forming the second electrode. The use of hydrogenated amorphous silicon carbide gives a layer enough resistivity so that the internal capacity of the photoconducting element gives the stocking capacity for the video cell thus simplifying the device.