9626371 McKittrick The development of high brightness, thermally stable, phosphor materials for display applications has become the limiting step in the development of new flat panel displays such as color plasma and field emission displays. Phosphors are luminescent materials when excited by an energy source such as an electron beam or photons and are composed of an inert host lattice with a small amount of dopant (activator). Most of the commercially available emissive display phosphors have been developed for high voltage, cathode ray tube applications which operate at 10-30 keV. There has been very little work done on developing new compositions for low voltage (100-10,000 eV) or plasma displays (UV emission at 147 nm). These new applications have demands on phosphors that are not optimized or met by the existing compositions. This project is to build a multipurpose workstation for the evaluation of cathodoluminescent and photoluminescent materials for applications in CRT screens, field emission devices and plasma displays. The workstation will consist of vacuum pumps, a vacuum chamber, a mass spectrometer, and a spectroradiometer with associated electronics for the evaluation of low and medium voltage cathodoluminescent phosphors. The UV evaluation will be performed by a commercially available luminescence spectrophotometer. %%% Our research has focused on the synthesis of novel phosphor powder compositions, the deposition of the powders to form highly adherent, dense screens and the characterization of the luminescent properties of these screens. We have concentrated our attention on understanding, modeling and predicting the luminescent behavior to ultimately improve the brightness, efficiency, and to decrease the emission decay time of high voltage phosphor screens. However, the role of surfaces (point and line defects, absorbed species, morphology, grain boundaries, etc.) is not understood on a fundamental level. Comparing the luminescent behavior of single crystals, powder screen and thin film phosphors will yield basic information on the how photoemission is affected by surfaces which in turn will aid in optimizing phosphor screens for display applications. ***
