title: Microporous phase-separated films of polymer blends for enhanced outcoupling of light from OLEDs.
abstract: Thin microporous films were formed by dropcasting a toluene solution containing various ratios of polystyrene:polyethylene glycol blends on a glass substrate, with OLEDs on the ITO that coated the opposite side of that substrate. We demonstrate for the first time that such easily-fabricated films with surface and bulk micropores in the index-matching polystyrene can serve as random microlens-like arrays to improve forward OLED light extraction by up to ~60%. A theoretical interpretation of the angular emission profile of the device, considering the geometrical change at the substrate/air interface and the scattering by the pores within the films, was established in excellent agreement with the experiments. The use of such blended thin films provides an economical method, independent of the OLED fabrication technique, for improving the outcoupling efficiency.
authors: Ames Laboratory - USDOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
authors: Rui
authors: R
authors: Liu
authors: Zhuo
authors: Z
authors: Ye
authors: Joong-Mok
authors: JM
authors: Park
authors: Min
authors: M
authors: Cai
authors: Ying
authors: Y
authors: Chen
authors: Kai-Ming
authors: KM
authors: Ho
authors: Ruth
authors: R
authors: Shinar
authors: Joseph
authors: J
authors: Shinar