Comparison of VUV and IR emission in an AC surface discharge with nanosecond time resolution

Abstract

Summary form only given, as follows. Vacuum ultraviolet (VUV) light emission from atomic Xe at 147 nm and the Xe/sub 2/ dimer at 173 nm are key to efficient operation of color ac plasma displays. Since these VUV emissions are blocked by glass in PDPs, the IR emission lines from Xe at 823 and 828 nm have previously been used as indicators of the discharge conditions and of the VUV. It is assumed that the 828 nm emission is roughly proportional to 147 nm Xe resonant emission, and that the 823 nm monitors the forming of metastable Xe, a precursor for Xe-dimer radiation at 173 nm. To test this, we have used a special discharge chamber with the MgF/sub 2/ window as a front panel and high speed driving electronics to detect simultaneously the VUV and IR emission. We have measured the current and light waveforms from a coplanar-surface-discharge-type panel with the photomultiplier as functions of driving voltage, total gas pressure, and Xe/Ne gas ratio. We find that the total VUV emission and the 173 nm Xe-dimer radiation increase rapidly as Xe concentration and the pressure increase, but the emission at 823 nm does not increase substantially. Thus the 823 nm line is a poor indicator of the 173 dimer emission. Also, the emission at 828 nm does not behave like the 147 nm resonance line except as a function of applied voltage. For example, the integrated 147 nm Xe resonant emission decreases above 10% Xe concentration because of radiation trapping. At 10% Xe concentration, the time- and spectrally integrated 173 nm Xe-dimer radiation exceeds the 147 nm Xe resonant radiation and we find that the VUV emission efficiency saturates. Also, we clearly observe the time delay between the dimer radiation and the resonant, atomic radiation, which reflects the dynamics of the dimer formation.