Enhancing the light out-coupling efficiency of organic light-emitting devices with random corrugated structures

The mismatch of refractive index at the interfaces of substrate, electrode/organic material will cause nearly 80% light losses in the organic light-emitting device (OLED). To solve this problem, a light extraction layer with random corrugated structures is fabricated with a quite simple method to enhance the light out-coupling efficiency of OLED. Compared with the planar OLED, about 21% enhancement of current efficiency is achieved in the corrugated OLED. This improvement comes from the scattering effect of polymer phase separation film, which can suppress surface plasmon polariton losses and reduce waveguide mode optical losses. In addition, the structures can decrease the angular dependence of the emission spectra in the planar OLED. With these advantages, the random corrugated structures provide the potential to be applicable to OLED for high-efficiency lighting and full-color display.