Structure formation in a DC-driven "barrier" discharge:

A DC-driven "barrier" discharge is a gas discharge layer and a high-Ohmic semiconductor layer sandwiched between planar electrodes to which a DC voltage is applied. The system resembles a dielectric barrier discharge, but is even simpler, as the external boundary conditions allow for a completely homogeneous and stationary state. Whole phase transition diagrams to purely oscillating states or to states with spatio-temporal structures were determined in experiments that actually explored the regime between Townsend and glow discharge. We discuss the experimental conditions and our present theoretical understanding, that is based on stability analysis and numerical solutions of a °uid model for the gas discharge with space charge e®ects and a linear model for the semiconductor.