PHOTOLUMINESCENCE ENHANCEMENT IN ORGANIC MICROCAVITY STRUCTURES

We have studied the photoluminescence properties of the metal chelates aluminum-tris(8-hydroxychinoline) (Alq(3)) and 1-(2-thienyl)-1,3-buta nediono)-1,10-phenanthroline europium(III) (Eu(TTFA)(3)Phen) sandwiche d between a planar Fabry-Perot microcavity structure. A strong influen ce of the position of the emission thin film on the luminescence spect ra has been observed. The emission intensity normal to the substrate s urface is drastically enhanced by an order of a magnitude if the activ e layer is placed at the antinode of the standing wave in the cavity. In comparison to non-resonant Alq(3) structures, the FWHM of the spect rum is reduced from 100 nm to about 20 nm. We also show that the Eu(TT FA)(3)Phen luminescence is spacially directed due to the inherent line width of only 5 nm.