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

摘要

This paper studies the visualization of the spatial distributionpattern of current density in a semiconductor photographic systemwith a gallium arsenide semiconductor photodetector. The spatialdistribution of the current in the filaments was determined byphotometric analysis of the gas discharge light emission when acurrent was passed through a photographic cell. This method ensuredspatial resolution of ～ 10/mm and made it possible to describequantitatively the distributions involv- ing a drop in currentdensity of ≥ 10~2. Transformation of the profile and amplitude ofthe current density of the filaments in the different regions of thecurrent voltage characteristic (CVC) has been studied. Thefilamentation (i.e. an inhomogeneous distribution of the currentdensity) was primarily due to the formation of a space charge ofpositive ions in the discharge gap between the photodetector and atransparent anode plate that changed the discharge from the Townsendtype to the glow type.