VUV spectroscopy of luminescent materials for plasma display panels and Xedischarge lamps

In plasma display panels and Xe discharge lamps, phosphors with a high quan tum efficiency under vacuum ultraviolet (VUV) excitation are required. Abso lute quantum efficiencies of such phosphors are usually be determined by us ing synchrotron radiation since the excitation wavelength can be freely tun ed over a wide energy range. A serious drawback of the use of synchrotron r adiation for this purpose is the accessibility towards research facilities and the time-consuming measurement procedure which is not in line with the fast pace of industrial phosphor development. We have built up a VUV spectr ophotometer which allows the measurement of absolute excitation and reflect ion spectra in the wavelength range of 115-350 nm. Additionally, a procedur e was developed to derive spectrally resolved quantum efficiencies from the se excitation spectra. In this work, the set-up of the VUV spectrometer is described and its performance is documented by comparing the obtained light output data of several phosphors with results recorded by using synchrotro n radiation. It is shown that also a relatively simple VUV spectrometer can be used to determine absolute light output and quantum efficiency data in the excitation range between 115 and 350 nm with an experimental error lowe r than 10%. (C) 2001 Elsevier Science B.V. All rights reserved.