High luminance and efficient GaN:Eu inorganic EL devices for monochromatic display applications

In this paper we report GaN:Eu AC-TDEL devices with high luminance and high efficiency levels obtained through optimized phosphor growth techniques and device structure. The GaN:Eu phosphor is grown using interrupted growth epitaxy (IGETM ). An improved thick dielectric layer for inorganic electroluminescent EL display devices has been achieved through a composite high-κ dielectric sol-gel/powder route. The reduction in thick dielectric porosity has improved the homogeneity of the electric field applied to the phosphor layer, resulting in a steeper luminance-voltage slope with a maximum luminance of ~1,000 cd/m2. Furthermore, the reduction in porosity has also decreased the diffuse reflection of the thick dielectric, which when pigmented, exhibits a diffuse reflectivity of <2% resulting in high display contrast.