A Color-Tunable Alternating Current Organic Light Emitting Capacitor

Wedemonstrate an alternating current (AC) driven light emittingcapacitor in which the color of the emission spectra can be changedvia an applied AC frequency. The device has a simple metal-oxide-semiconductor(MOS) capacitor structure with an organic emissive layer, enablingfacile fabrication processing. The organic emissive layer comprises a thin, submonolayer low energy dye layer underneath a thick hostmatrix (similar to 30 nm) with higher energy emitting dyes. The emissionof the lower energy dyes dominates at low frequency, while the higherenergy emission of the host matrix dominates at high frequency. Thissimple color tunable device could be used for full-color displaysand lighting in the future.