Dual pattern for enhancing light extraction efficiency of white organic light-emitting diodes

Nano and micro-patterns (dual patterns) were introduced on a glass substrate as an extraction layer to enhance the light extraction efficiency of white organic light-emitting diodes (WOLEDs). The dual-patterned glass was fabricated by thermal evaporation, direct printing, and reactive ion etching. The combination of nano- and micro-structures imparted highest current density and luminance to the dual-patterned WOLED without electrical degradation. Additionally, the dual-patterned WOLED exhibited higher current and power efficiencies compared to that of the nano- and micro-patterned WOLEDs, which increased by 21% and 27% at 1 mA/cm2, respectively, as compared to that of the reference.