High light-extraction-efficiency OLED based on photonic crystal slab structures with taper unit cells

To improve the light-extraction-efficiency of OLED,we introduced PCS (Photonic Crystal Slab) structures into the interface of ITO layer and glass substrate.PCS structures with Taper unit cells are proved to be effective in reducing the energy of guided wave trapped in high refractive index material,and an increase of light-extraction-efficiency to 95.26% is gained.This enhancement is much greater than the traditional PCS with cylinder unit cells (60%-70%).Physical mechanisms of light-extraction-efficiency enhancement in these structures are further discussed.