Study On The Effect Of Barrier Material On Characteristic Of Dielectric Barrier Discharge

Dielectric barrier discharge (DBD) is regarded as an important way to get uniform discharge plasma in large area, which shows promising future in industrial applications and great benefit in economy and environment protection. But in atmospheric air, it is difficult to get uniform discharge. Because dielectric barrier material affect the characteristic of DBD greatly, it is very important to investigate the effect of barrier materials on discharge for getting uniform discharge in large areas.Alumina, quartz, polypropylene (PP), Polytetrafluoroethylene (PTFE) and silicone rubber (SIR) have been used as barrier material separately to study the property of DBD in low pressure air. By using the test devices and measurement system, the discharge form and the range of pressure to get uniform discharge have been investigated to estimate the influence of materials on DBD. The results show that, the pressure range of homogenous discharge obtained by the organic materials is much wider than that obtained by inorganic materials.The temporal quantities of surface charge on five different materials have been measured. According to the test data, both the properties of accumulating and keeping charge affect the characteristic of DBD. It is comfirmed that desorption of surface electrons influences the discharge greatly.The thermally stimulated current testing has been applied to measure the trapping distribution in different materials. The result shows that the density of trapping centers lower than 1 eV is a crucial fuction for the pressure range of uniform discharge. The higher the density of trapping centers less than 1 eV located in the material is, the wider the pressure range for getting uniform discharge is.Under the analysis of trapping data, the mechanisms related to the desorption of electrons on the surface of barrier material in DBD have been discussed. It could be metastables staying in the gas to create initial electrons secondary emission by escaping them from the materials.According to the fact of trapping distribution affecting DBD, the new barrier material of aging silicone rubber with more trapping lower than 1 eV has been found as dielectric barrier material. By using it, uniform discharge could be obtained in a wider pressure range. It shows a new available way to obtain homogenous discharge in a large area in atmospheric air.