Organic Light Emitting Diode with Uniform Luminance Distribution and Enhanced Efficiency via Random Embossing Structure

Abstract

Using the lateral phases separation of a binary immiscible polymer blend, we have fabricated a random embossing structure (RES). The RES was investigated as a potential structure for organic light-emitting diode (OLED) light extraction. Our RES yields uniform light extraction in a broad angle (0 degrees similar to 70 degrees) range with spectral stability. Blue phosphorescence OLEDs equipped with the RES showed an enhancement of 20% in external quantum efficiency (EQE) and spectral stability within Delta x, y < 0.01 in a viewing angle range of 0 degrees similar to 70 degrees. Our RES provides a new and practical approach for achieving enhanced efficiency and spectral stability of OLEDs. (C) 2014 The Electrochemical Society. All rights reserved.