Improvement of plasma uniformity using ZnO-coated dielectric barrier discharge in open air

Summary form only given. The discharge behavior in atmospheric pressure dielectric barrier discharge (DBD) using ZnO-coated dielectric layer are examined. Using RF magnetron sputtering, ZnO thin film deposited on the alumina surface represents the higher surface conductivity of about 10⁶ orders than bare alumina surface. And we made two types of DBD reactor, normal DBD using bare alumina and ZnO-coated DBD. The size of the area was 5 cmtimes2 cm for dielectric layer and 3 cmtimes1 cm for copper electrode. Negative DC pulse power was applied to each reactor. And the pulse was generated by thyratron switching element and applied frequency is 1 kHz. Experimental result shows that in case of ZnO-coated DBD, discharge uniformity is improved definitely. Increase of surface conductivity causes charge spreading over the dielectric surface widely and these charges play a role of seed electrons for the initiation of consecutive streamer. Therefore the radius of microdischarge in air is decreased but fine and numerous current pulses are generated. This situation enhances the uniformity and stability of atmospheric pressure discharge in open air