Microcavity organic light-emitting diodes for strongly directed pure red, green, and blue emissions

In this article we demonstrate strongly directed pure red, green, and blue emissions in the organic light-emitting diodes (OLEDs) with a planar microc avity defined by a pair of dielectric mirror and a metal mirror. By careful control of the cavity mode and the position of the resonance wavelength, t he strong directionality in the forward direction as well as the spectral n arrowing and the intensity enhancement are realized in the microcavity OLED s. The intensity enhancements at the resonance wavelength are 1.5-5 compare d to the noncavity OLEDs, and the chromaticity coordinates of the emission colors are the ideal primary colors. The experimental results are compared to theoretically calculated ones. (C) 1999 American Institute of Physics. [ S0021-8979(99)07317-X].