Spatiotemporal Transport Processes in Semiconductor Gas Discharge Structure with GaAs Photodetector

In a semiconductor gas discharge structure with diameters much larger than an inter-electrode distance, the effects of different parameters (i.e. electrode separation, gas pressure, diameter of the GaAs photodetector, etc.) on electrical breakdown and current oscillations were studied. Non-stationary and non-homogeneous states are generated in the structure, through the spatially uniform irradiation of the semiconductor photodetector. Instabilities occur due to the nonlinear features of the semiconductor photocathode, while the gas discharge serves to visualize transport processes in GaAs. Spatiotemporal variations of current and discharge light emissions are studied with the above-mentioned control parameters. Transformation of the profile and amplitude of the current densities of the filaments in different regions of the current-voltage characteristic are widely studied. Instabilities of spatially non-uniform distributions resulting in the formation of multiple current filaments with increasing voltages above the critical values are observed. A semiconductor gas discharge structure with an N-shaped current-voltage characteristic is analyzed via both the current and discharge light emissions data which shows the electrical instability in the GaAs photodetector.