Blue top-emitting organic light-emitting devices based on wide-angle interference enhancement and suppression of multiple-beam interference

摘要

Blue top-emitting organic light-emitting devices (TEOLEDs) based on blue phosphor indium (III) bis[(4,6-difluorophenyl)-pyridmato-N,C~2'] picolinate (Flrpic) are demonstrated. Instead of using microcavity effects to obtain the blue top emission in conventional reports, the blue emission with a good chromaticity is achieved in this paper through the suppression of the multiple-beam interference by introducing a 2,9-dimethyl-4,7-diphenyl-1,10-phenanthro-line light outcoupling layer onto the semitransparent Sm/Ag cathode. The electroluminescent performances of the blue emission is further improved based on the effective carrier transport and the consideration of the wide-angle interference at the emission peak of FIrpic with a maximum luminance of 8029 cd/m~2 and a luminous efficiency of 4.02 cd/A achieved at 14 V and 10 V, respectively. With a polarizer on the top cathode, a high pixel contrast ratio of 113:1 is realized under an ambient illumination of 140 lx and a pixel brightness of 1000 cd/m~2.