Visualization of the spatial distribution of current densities in a photographic system with a semiconductor photodetector

This paper studies the visualization of the spatial distribution pattern of current density in a semiconductor photographic system with a gallium arse nide semiconductor photodetector. The spatial distribution of the current i n the filaments was determined by photometric analysis of the gas discharge light emission when a current was passed through a photographic cell. This method ensured spatial resolution of similar to 10/mm and made it possible to describe quantitatively the distributions involving a drop in current d ensity of greater than or equal to 10(2). Transformation of the profile and amplitude of the current density of the filaments in the different regions of the current-voltage characteristic (CVC) has been studied. The filament ation (i.e. an inhomogeneous distribution of the current density) was prima rily due to the formation of a space charge of positive ions in the dischar ge gap between the photodetector and a transparent anode plate that changed the discharge from the Townsend type to the glow type.