Highly efficient OLED achieved by periodic corrugations using facile fabrication

In this study, a newly facile method for fabricating corrugations as light extractor in OLED was developed. The corrugated structure fabricated using simple polymer molding and ultraviolet (UV) forming was identified to feature high transmittance of 87.5 % and a haze of 38.5 % in UV–vis wavelength range, respectively, promoting the light extraction. Consequently, compared with planar OLED, corrugated OLED with period of 417 nm was found to exhibit a significant increase in external quantum efficiency (ηEQE), rising from 25.5 % to 34.0 %, while maintaining identical electrical characteristics. In addition, attaching a macro-lens to further improve the ηEQE by an impressive 52.6 %. Overall, a remarkable enhancement of 106.2 % was achieved through internal corrugation combined with an external lens, which can be attributed to the reduction of total internal reflection in waveguide and substrate modes, along with minimized light loss in surface plasmon polariton mode. These findings highlight the potential of periodic corrugated structures in realizing efficient OLEDs for lighting or next generation displays.