Dielectric barrier discharge(DBD) is widely investigated in order to obtain uniform low-temperature plasma.Many studies have proved that some barrier materials,especially electrets,can improve the uniformity of discharge.It is regarded as an available way to get atmospheric pressure glow discharge(APGD).In this paper,discharge forms with 4 different barrier materials(alumina,quartz,PTFE and PET) are investigated,and the transition of discharge form depending on the air pressure are recorded to estimate the influence of barrier materials on discharge.By using electrets as barrier materials,homogeneous discharges can be obtained in a more wide pressure range.Under the same experimental conditions,discharges with electrets are more uniform or have larger uniform areas due to the storage and desorption of charges on the surface of electrets.The electrons deposited in the surface layer can be released on next half cycle when the polarity of the applied voltage changes,and provide a number of seed electrons,which makes the discharge more homogeneous.The capacitance and the permittivity of barrier materials have no effect on the discharge form directly.
LIMing LI Cheng-rong ZHAN Hua-mao XU Jin-bao ZHANG Xian-jun
