Implications of microcavity plasma devices for new plasma-display-panel cell structures with improved luminosity

Abstract

— The unique properties of microcavity plasma devices, and their potential to provide the basis for alternative PDP cell structures of improved luminosity, are described. Arrays as large as 500 × 500 (250,000) inverted pyramid microcavity devices, each with an emitting aperture of 50 × 50 μm2 and designed for AC or bipolar excitation, have been fabricated in Si and operated in the rare gases and Ar/N2 mixtures at pressures up to and beyond 1 atm. For a device pitch of 100 μm, the array filling factor is 25% and the device packing density is 104 cm−2. Measurements of the unoptimized radiant output of 500 × 500 arrays of Si microplasma devices, operating in Ne/(5–50)% Xe mixtures and photoexciting (in transmission mode) a 20-μm-thick film of green phosphor, yield values of the luminous efficacy up to 7.2 ± 0.6 lm/W for a Ne/50% Xe mixture (total pressure of 800 Torr) excited by a 20-kHz sinusoidal voltage waveform. Sustaining voltages ranging from ∼250 to 340 V (RMS) yield luminance values up to ∼2000 cd/m2 for Ne/50% Xe mixtures but the incorporation of field emitters or MgO into the microcavity is expected to significantly reduce the required operating voltage. Also, the fabrication of microplasma devices in ceramic multilayer structures or glass for scaling the display area is discussed briefly. Recent laser spectroscopic measurements of Xe(a 3Σu+) absorption in the visible and near-infrared suggest steps to be taken in PDP cell design, particularly as the Xe content in Ne/Xe mixtures is increased.