Organic Light-Emitting Devices Using Photonic Crystals

Photonic crystals (PCs) have attracted considerable attention because of their wide range of applications to nanoscale photonic devices. In this article, we review and show applications of PCs to organic light-emitting devices. One of the applications is the improvement of light-extraction efficiency of organic light-emitting diodes (OLEDs). Electroluminescence spectra of OLEDs with a PC depend on the PC structure, in particular, the lattice constant of the PC. Design of a PC with specific lattice constant and its subsequent incorporation into an OLED can improve the light-extraction efficiency. The other application considered is that of photonic nanocavities emitting in the visible-light range. Such nanocavities have been demonstrated using air-bridge photonic crystal based on organic materials, and are reviewed here. Results showing the possibility of chemical sensors using nanocavities are also presented.