Nonequilibrium atmospheric pressure plasma with ultrahigh electron density and high performance for glass surface cleaning

We produced a nonequilibrium atmospheric pressure plasma by applying an alternative current between two electrodes. The gas temperature and electron density were evaluated using optical emission spectroscopy. It was found that the plasma had gas temperatures from 1800 to 2150 K and ultrahigh electron densities in the order of 10(16) cm(-3). A remarkably high oxygen radical concentration of 1.6 x 10(15) cm(-3) was obtained at a 1% O-2/Ar gas flow rate of 15 slm (standard liters per minute). Contact angles below 10 degrees were obtained in the process of glass cleaning with a plasma exposure time of 23 ms. (C) 2008 American Institute of Physics.