Investigation of DC -driven Glow Discharges in Subatmospheric Planar AlGaSb-Ar/He Microplasma System

Abstract

Various studies have been reported on the theoretical and experimental investigation of planar DC -driven gas discharge-semiconductor micro plasma systems (GDSµPS) for infrared sensing and thermal image conversion applications. This conceptual research study is carried out to investigate the infrared-stimulated semiconductor-micro plasma hybrid systems using the finite-element method (FEM) solver COMSOL Multiphysics plasma simulation program. The computational simulation in this study was carried out based on the boundary-separated mesh structure to visualize the spatio-temporal distribution of Electron Density (ED) and Electron Current Density (ECD) patterns across planar discharge cell. Numerical analyses were performed based on mixture-averaged diffusion drift theory and Maxwellian electron energy distribution function. The micro plasma reactor cell is composed of a planar anode/cathode electrode pair in a 2-dimensional square chamber separated at a gap distance of 100 µm. A III-antimonide compound semiconductor, Aluminum Gallium Antimonide (AlGaSb), with micron-scale digitized electron emission surface is coupled to argon/helium (Ar/He) gas medium mixed in various (%) molar fractions at a constant total pressure of 200 Torr sub atmospheric. The electrical equivalent circuit model is driven at 1.350 VDC by virtual voltage source. The fast transient DC glow discharges are simulated for each mixture model, the spatio-temporal curves and patterns are displayed in multidimensional graphical media, compared, and analyzed with respect to the reference model. It is figured out that binary Ar/He gas discharge system plays an important role in shaping the glow discharge characteristics of GDSµPS for bandgap-tunable infrared-to-visible wavelength conversion device application. In the end, argon mixed with helium at a molar fraction of 30% is proposed for the intended infrared image converting concept by this study.