Luminescence behavior of Eu(TTFA)(3) doped sol-gel films

The formation and the luminescence behavior of the Eu(TTFA)(3) sol-gel film s have been investigated. The Thenoyltrifluoroacetone (TTFAH) was dissolved in ethanol in advance, and then the EuCl3 and ethanol containing TTFAH wer e introduced into the initial precursor sol. The precursor sol was dip-coat ed onto substrates to form Eu(TTFA)(3) doped sol-gel films. The luminescenc e intensity of the Eu(TTFA)(3) doped sol-gel films was significantly increa sed with the increase of film thickness. However, there existed an efficien t luminescence layer in the Eu(TTFA)(3) doped sol-gel films. The luminescen ce intensity did not increase when increasing the film thickness above the thickness of the efficient luminescence layer. The thickness of the efficie nt luminescence layer was related to the Eu(TTFA)(3) concentration in the f ilm. The higher the Eu(TTFA)(3) concentration, the thinner the efficient lu minescence layer. The heat treatment temperature of the films had also infl uence on the luminescence intensity. With the increase of the temperature, the Eu(TTFA)(3) formed gradually and luminescence intensity increased. But when the temperature was higher than 150 degrees C, the luminescence intens ity decreased rapidly due to the decomposition of the Eu(TTFA)(3). (C) 1999 Elsevier Science S.A. All rights reserved.