Analysis of prebreakdown current in a gas discharge system with a semiconducting cathode

Results are presented of an analysis of the prebreakdown current of a Townsend discharge in a planar gas discharge system with a GaAs semiconductor cathode for a gap thickness of 45 mu m and gas pressures of 6.9, 8.9, 34.2 and 36.9 kPa. IR radiation excites the cathode in the system, thus controlling the current density in the gas discharge layer. It is shown that the prebreakdown current is caused by electron emission from the semiconductor surface. The present experimental investigations show that the prebreakdown current decreases anomalously with increase of the feeding voltage and that it also decreases under the illumination of a semiconductor cathode. Both these anomalies depend on gas pressure. The current density change through the cross-section of the discharge gap, i.e. the appearance of the spatio-temporal self-organization of non-linear dissipative systems, causes these observed effects. These characteristics of the system can be applied for fast IR imaging and a high speed UV light source.