高效率上發光有機發光元件的開發

Abstract

We have developed highly efficient red, green and blue top-emitting organic light-emitting devices by using Ag as the anode and cathode. We optimized microcavity effect in the devices by tuning suitable optical length for RGB emissions. A very saturated RGB color with Commission Internationale d’Eclairage (CIE) coordinates of (0.646, 0.353), (0.227, 0.721) and (0.135, 0.056) for RGB respectively were demonstrated and shown to display a color gamut of NTSC 102%. We also introduced a new hole-injection layer to get better carrier balance in the TOLEDs with which one of the best electroluminescence (EL) efficiencies for red was achieved at 37.5 cd/A .

We have also developed highly efficient white top-emitting organic light-emitting devices with broad emission by modifying both the anode and cathode. To alleviate the undesirable microcavity effect and obtain “broad” white emission, a CFx-coated Ag anode and an index-matching layer (SnO2) capped on a thin Ca/Ag cathode with a maximum transparency of 80% were employed. A top-emitting broad white-light device, based on the dual-layer architecture of light blue and yellow emitters with one of the highest EL efficiencies of 22.2 cd/A (9.6 lm/W) at 20 mA/cm2 and 7.3 V with CIE coordinates of (x＝0.31, y＝0.47), has been demonstrated.