LUMINESCENCE ENHANCEMENT IN MICROCAVITY ORGANIC MULTILAYER STRUCTURES

We have studied the photoluminescence properties of aluminum-tris(8-hy droxychinoline) (Alq(3)) and 1-(2-thienyl)-1,3-butanediono)-1,10-phena nthroline europium(III) (Eu(TTFA)(3)Phen) sandwiched between a planar Fabry-Perot microcavity structure. A strong influence of the position of the emission thin film on the luminescence spectra has been observe d. The emission intensity normal to the substrate surface is drastical ly enhanced by an order of a magnitude if the active layer is placed a t the antinode of the standing wave in the cavity. In comparison to no n-resonant Alq(3) structures, the full width at half-maximum (FWHM) of the spectrum is reduced from 100 to about 20 nm. We also show that th e Eu(TIFA)(3)Phen luminescence is spatially directed due to the inhere nt linewidth of only 5 nm. (C) 1997 Elsevier Science S.A.