Efficient and angle-stable white top-emitting organic light emitting devices with patterned quantum dots down-conversion films

Efficient white top-emitting organic light-emitting devices (TEOLEDs) are fabricated by combining blue TEOLEDs with down-conversion films. Quantum dots (QDs) are integrated with polymethyl methacrylate (PMMA) to obtain freestanding composite films, and the films are used as down-conversion films to produce red emission by converting blue emission from blue TEOLEDs. The blue and white TEOLEDs exhibit the maximum current efficiency of 37.4 and 22.2 cd/A, respectively. Through integrating a microstructure QDs down-conversion film by transfer printing on blue TEOLED, the light extraction performance of white TEOLEDs is improved and the angular distribution of the white emission is almost Lambertian. The CIE color coordinates of white TEOLEDs with patterned QDs down-conversion films shift only (0.025, 0.005) from 0 degrees to 60 degrees.