52.1: Invited Paper: Highly Efficient White Top‐Emission PIN OLEDs for Display and Lighting

Here we report high efficiency white top-emission (TE) OLEDs for display and lighting applications. Featuring sputtered ITO top contact, thin film encapsulation (TFE) and out-coupling layers on top, high performance white TE OLEDs are demonstrated with power and external quantum efficiencies of 25 lm/W and 25%, respectively. Similar high efficiencies are also presented for top-emission devices built on bendable metal substrates with a thickness of only 0.2 mm. Both types of devices have broad spectra with 1931 CIE color coordinates of 0.38/0.37 on glass and 0.43/0.40 on the metal substrate. The color rendering index (CRI) reaches a value of 80. In another white top-emission OLEDs approach, semitransparent metal top contacts are combined with a scattering cap layer to achieve a high power efficiency of up to 20 lm/W. Those devices exhibit extremely stable color coordinates over a wide range of viewing angles, which is attributed to the scattering behavior of the cap layer material.