Ronald O. Petersen

Degradation Mechanisms and Vacuum Requirements for Fed Phosphors

Degradation of phosphors in field emission displays (FEDs) is described and related to electron beam stimulated surface reactions between ZnS and residual gas in the vacuum system. The requirements for producing and maintaining vacuums in FED packages is reviewed and limitations associated with the size of the FEDs are discussed. It is concluded that vacuum production and maintenance is critical to the performance of FEDs, and this is not a simple task.

Development of Field Emission Flat Panel Displays at Motorola

Over the past few years, Motorola, as well as several other companies around the world, have been developing a new type of flat panel display, called the field emission display (FED). The FED combines many of the advantages of its cousin, the cathode ray tube (CRT), including high brightness and contrast, wide angle viewability, and speed in a flat package that is only a few millimeters thick. A 14 cm diagonal FED prototype built at Motorola Flat Panel Display Division is shown below, in Figure 1.

Electron stimulated desorption of FED phosphors

Field emission cathode arrays are sensitive to contamination by residual gases present in the vacuum envelope. One source of such gases in packaged field emission displays is the electron beam induced desorption of display phosphors. In this paper, we report measurements of electron stimulated desorption (ESD) of gaseous species from two blue powder phosphors, namely Y/sub 2/SiO/sub 5/:Ce and ZnS:Ag,Cl. The ESD measurements were made for beam energies from 100 to 5000 eV, with DC current densities of 10 to 200 /spl mu/A/cm/sup 2/. The gas species evolved from phosphor desorption were analyzed with a high resolution quadrupole mass spectrometer placed directly in line of sight of the excitation area.

300 V Cathodoluminescent Efficiency and Degradation

With the possible commercialization of field emission display devices, low voltage phosphor performance has regained interest. Summarized in this presentation is 300 volt efficiency and electron degradation results for various RGB phosphor candidates.