The microcavity organic light emitting diode with glass/Ag/PVK/Alq

3

/Al struct ure wa s fabricated using a typical emitting material

tris(8-quinolinolato)aluminu m

which is different from the conventional microcavity structure of Glass/DBR/ITO/Organic layers/Al. Because there is penetrate depth of about 1～1.5 λ (resonant wavelength) in DBR

it is difficult to realize single mode emitting. In our stru cture we used a thin metal layer to replace DBR/ITO acting as reflector and anode. The metal layer has very small penetrate depth and be easy to realize single mode emitting. The variation of mode density in microcavity as well as spectral narrowing and intensity enhancement were realized. The pure three color emission is observed and the intensity enhancement at resonance wavelength are increased by factor of 2～2.5. And the spectral halfwidths are narrowed by a factor of 1/3 compared to that of non-cavity OLED(100nm).