出版社：Electronics and Telecommunications Research Institute
摘要：We developed a highly refractive index planarization layer showing a very smooth surface for organic light-emitting diode (OLED) light extraction, and we successfully prepared a highly efficient white OLED device with an embossed nano-structure and highly refractive index planarization layers. White OLEDs act as an internal out-coupling layer. We used a spin-coating method and two types of solutions for a planarization of the embossed nano-structure on a glass substrate. The first solution was sol, which consists of colloidal particles in an acidic aqueous solution and several organic additives. The second solution was an organic and inorganic hybrid solution of . The surface roughness ( ) and refractive index of the planarization films on a flat glass were 0.4 nm and 2.0 at 550 nm, respectively. The J-V characteristics of the OLED including the embossed nano-structure and the planarization film were almost the same as those of an OLED with a flat glass, and the luminous efficacy of the aforementioned OLED was enhanced by 34% compared to that of an OLED with a flat glass.
