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http://dx.doi.org/10.3807/HKH.2007.18.6.441

Outcoupling Enhancement of OLED using Microlens Array and Diffractive Grating  

Jang, Ji-Hyang (Nano-Bio Photonics Lab., Department of Electronics Engineering, Pusan National University)
Kim, Kyung-Jo (Nano-Bio Photonics Lab., Department of Electronics Engineering, Pusan National University)
Kim, Jin-Hun (Nano-Bio Photonics Lab., Department of Electronics Engineering, Pusan National University)
Oh, Min-Cheol (Nano-Bio Photonics Lab., Department of Electronics Engineering, Pusan National University)
Publication Information
Korean Journal of Optics and Photonics / v.18, no.6, 2007 , pp. 441-446 More about this Journal
Abstract
Outcoupling efficiency of the OLED device is improved by incorporating both a microlens array and a diffractive grating pattern. The microlens array improves the light transmission at the interface of glass and air, and the diffractive grating outcouples the guided mode propagating at the waveguide, which consists of ITO and organic layers. By using the PDMS soft mold imprinting method, the microlens array is fabricated on the glass substrate. The diffractive grating pattern is directly fabricated on the ITO surface by using laser interferometry. A microlens array with a diameter of $10{\mu}m$ improves the light coupling efficiency by 22%. The diffractive grating made of TSMR photoresist enhances the luminance power efficiency by 41% at a current density of $20mA/cm^2$.
Keywords
OLED; Outcoupling enhancement; Microlens array; Diffractive grating; Nano-imprinting;
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