In order to increase the out-coupling efficiency of organic light emitting diodes, conical Si oxide nanostructures were formed on a glass substrate using nanoimprint lithography with hydrogen silsesquioxane. Then, the substrate was planarized with TiO2 nanoparticles. Since TiO2 nanoparticles have a higher refractive index than Si oxide, the surface of substrate is physically flat, but optically undulated in a manner that enables optical scattering and suppression of total internal reflection. Subsequently, OLEDs formed on a substrate with nanostructured Si oxide and a TiO2 planarization layer exhibit a 25% increase in out-coupling efficiency by suppressing total internal reflection.
Bibliographical noteFunding Information:
This research was supported by the Pioneer Research Center Program through the National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning ( NRF-2013M3C1A3063597 ). This work was supported by the National Research Foundation of Korea grant funded by the Korea government(MSIP) ( 2016R1A2B3015400 ). This research was supported by LG Innotek KoreaUniversity Nano-Photonics Program.
- Light extraction
- Refractive index
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- General Computer Science
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Electrical and Electronic Engineering