ELECTROLUMINESCENT MATERIAL FOR FLAT PANEL DISPLAY

The purpose of this Cooperative Research and Development Agreement (CRADA) was to develop a new-generation electroluminescent (EL) material for flat panel displays and related applications by using unique and complementary research capabilities at Oak Ridge National Laboratory and OSRAM Sylvania, Inc. The goal was to produce an EL material with a luminance 10 times greater than conventional EL phosphors. An EL material with this increased luminance would have immediate applications for flat panel display devices (e.g., backlighting for liquid-crystal diodes) and for EL lamp technology. OSRAM Sylvania proposed that increased EL phosphor luminance could be obtained by creating composite EL materials capable of alignment under an applied electric field and capable of concentrating the applied electric field. Oak Ridge National Laboratory used pulsed laser deposition as a method for making these composite EL materials. The materials were evaluated for electroluminescence at laboratory facilities at OSRAM Sylvania, Inc. Many composite structures were thus made and evaluated, and it was observed that a composite structure based on alternating layers of a ferroelectric and a phosphor yielded electroluminescence. An enabling step that was not initially proposed but was conceived during the cooperative effort was found to be crucial to the success of the composite structure. The CRADA period expired before we were able to make quantitative measurements of the luminance and efficiency of the composite EL material. Future cooperative work, outside the scope of the CRADA, will focus on making these measurements and will result in the production of a prototype composite EL device