6 Matching Results

Search Results

Advanced search parameters have been applied.

in creator/contributor: "Shea, L.E."

open access

Cathodoluminescent display phosphors

The past several years rendered a resurgence of interest in phosphors for low-voltage flat panel displays utilizing cathodoluminescence (CL). A major selection criterion for these phosphors is CL efficiency. The objective is to maximize the efficiency at low voltages. This work focuses on understanding the materials properties that influence CL efficiency below 1 kV. Existing high-voltage CL efficiency models take into account intrinsic materials properties such as band-gap energy. Experimental… more

Date: January 4, 2000

Creator: Shea, L.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Development of Standards for Characterization of Cathodoluminescence Efficiency

Cathodolurninescence (CL) characterization in a demountable vacuum chamber is an important benchmarking tool for flat-panel display phosphors and screens. The proper way to perform these measurements is to minimize the effects of secondary electrons, excite the phosphor/screen with a uniform beam profile, and maintain a clean vacuum environment. CL measurements are important for preliminary evaluation and lifetesting of phosphor powders and screens prior to incorporation into the FPD. A survey … more

Date: January 20, 1999

Creator: Shea, L.E. & Walko, R.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Effects of processing on the low-voltage performance of cathodoluminescent garnet phosphors

Field emission flat panel displays place new demands on the performance of cathodoluminescent phosphors. In particular, such phosphors must be efficient at lower voltages (ca. 100-1000 V), and must withstand higher current densities than are present on cathode ray tube screens. ZnO:Zn has been studied extensively as a low-voltage phosphor, but problems such as poor chromatic saturation and temperature sensitivity of emission remain. In this work the use of terbium-doped garnet phases such as yt… more

Date: August 1, 1995

Creator: Phillips, M.L.F. & Shea, L.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Combustion synthesis and effects of processing parameters on physical properties of {alpha}-alumina

Fine particle porous {alpha}-alumina has been prepared by a wet chemical method of combustion synthesis using an aqueous precursor containing aluminum nitrate (oxidizer) and carbohydrazide, an organic fuel as starting materials. The aluminum nitrate and carbohydrazide were reacted exothermically at 400--600 C. The synthesis of {alpha}-alumina ({alpha}-Al{sub 2}O{sub 3}) was used as a model for understanding the effects of processing parameters on physical properties such as surface area, averag… more

Date: January 4, 2000

Creator: Collins, M.V.; Hirschfeld, D.A. & Shea, L.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Phosphor synthesis routes and their effect on the performance of garnet phosphorus at low-voltages

Garnet phosphors have potential for use in field emission displays (FEDs). Green-emitting Gd{sub 3}Ga{sub 5}O{sub 12}:Tb (GGG:Tb) and Y{sub 3}Al{sub 5}O{sub 12}:Tb (YAG:Tb) are possible alternatives to ZnO:Zn, because of their excellent resistance to burn, low-voltage efficiency, (3.5 lm/W from GGG:Tb at 800 V), and saturation resistance at high power densities. Hydrothermal and combustion synthesis techniques were employed to improve the low-voltage efficiency of YAG:Tb, and Y{sub 3}Ga{sub 5}O… more

Date: July 1, 1996

Creator: Shea, L.E.; McKittrick, J. & Phillips, M.L.F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Garnet phosphors prepared via hydrothermal synthesis

This project studied hydrothermal synthesis as a route to producing green-emitting cathodoluminescent phosphorus isostructural with yttrium aluminum garnet (Y{sub 3}Al{sub 5}O{sub 12}, or YAG). Aqueous precipitation of Y, Gd, Al, Ga, and Tb salts produced amorphous gels, which were heated with water at 600 C and 3,200 bar to produce crystalline YAG:Tb, Y{sub 3}Ga{sub 5}O{sub 12}:Tb, Y{sub 3}Al{sub 3}Ga{sub 2}O{sub 12}:Tb, and Gd{sub 3}Ga{sub 5}O{sub 12}:Tb powders. Process parameters were ident… more

Date: May 1, 1996

Creator: Phillips, M.L.F.; Walko, R.J. & Shea, L.E.

Item Type: Report

Partner: UNT Libraries Government Documents Department