Extracting optical modes of organic light-emitting diodes using quasi-periodic WO3 nanoislands.

Quasi-periodic WO(3) nanoislands are introduced to extract two optical modes in organic light-emitting diodes. The nano-scaled and size-tunable WO(3) islands were fabricated by use of wet-etching with self-aggregated Ag mask. The improvement of light extraction efficiency originates to the recovery of light losses which are surface plasmon mode and waveguide mode. As a result, external quantum efficiency and power efficiency were increased. No changes in emission spectrum and CIE color coordinates with WO(3) nanoislands at various observation angles are desirable if this device is to be utilized in optical system. Furthermore, cost-effective fabrication makes it possible to adopt this system in large area fabrication.