Top-emitting organic light-emitting devices with improved light outcoupling and angle-independence

An organic capping layer has been used to increase the light output of the top-emitting organic light-emitting device (TEOLED) employing highly reflective Ag as anode and semitransparent Ag as cathode. The transmittance of the cathode with a 50 nm thick optimized top-capping layer for a wavelength of 520 nm is nearly twice that of the controlled device. Accordingly, an efficient TEOLED capped with a 50 nm thick refractive index-matching layer had been fabricated. Especially, together with the independence of the view angle for the emission peak, the luminance and efficiency for the TEOLED at low voltage (4 V) are 677 cd m(-2) and 15 cd A(-1), respectively, as was desired for the displays.