White Light from GaN/Conjugated Polymer Hybrid LEDs

This Phase I SBIR Proposal outlines a program directed toward the development of highly efficient white light sources or multiple color sources by combining the photoluminescence from semiconducting conjugated polymers with the emission from high efficiency Group III-Nitride based LEDs; the Group III-Nitride LED provides the blue component of the emission spectrum and, simultaneously, serves as the short wavelength pump source for exciting the photoluminescence of the polymer film(s). The achievement of white light and/or multiple color LEDs from the InGaN system is difficult and costly. In the proposed Group III-Nitride/Polymer hybrid LED, the polymer film(s) can be mounted directly on the Group III-Nitride chip and included within the Group III-Nitride LED package. As the quantum efficiency of the Group III-Nitride LEDs is further improved from the present level of 7% to anticipated levels in excess of 15%, major opportunities will emerge. In particular, by using the Group III-Nitride/ luminescent polymer hybrid which is the focus of this Phase I proposal, white lighting sources which are substantially more efficient than tungsten light bulbs are expected to result. The development and commercialization of solid state white light sources which are more efficient than tungsten light bulbs, will have a major impact. These devices will enjoN advantages of longer service life, increased heat resistance and resistance to mechanical shock, higher energy efficiency, and lower cost than existing alternatives. The cost advantapes alone could have a dramatic effect on the operating budgets of themilitary and civilian sectors of the economy.