Photo-luminescence in a conjugated polymer/glass composite ®lm A. Donval a,* , D. Josse a , G. Kranzelbinder a , R. Hierle a , E. Toussaere a , J. Zyss a , G. Perpelitsa b , O. Levi b , D. Davidov b , I. Bar-Nahum c , R. Neumann c a Laboratoire de Photonique Quantique et Mole Âculaire UMR CNRS # 8537), Ecole Normale Supe Ârieure de Cachan, 61 av. du pre Âsident Wilson, Cachan 94235, France b Racach Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel c Department of Organic Chemistry, Weizmann Institute of Sciences, Rehovot 76100, Israel Abstract We report on the chemistry, ®lm preparation properties and ampli®ed spontaneous emission ASE) features of a polytetramethoxy- phenylenevinylene) PTMPV) conjugated polymer blended with a zirconium±organosilicon xerogel glassy matrix. We also report on a waveguide con®guration using PTMPV polymer. # 2001 Elsevier Science B.V. All rights reserved. Keywords: Photo- and electro-luminescence; Ampli®ed spontaneous emission; Sol±gel; Conjugated polymer; Waveguide 1. Introduction The polytetramethoxy-phenylenevinylene) PTMPV) conjugated polymer is found attractive for photo- and elec- tro-luminescence processes due to the availability of a broad Stoke's spectral shift from the absorption to ¯uorescence emission spectra. This enhanced gap is indicative of a favor- able potential towards ef®cient ampli®ed spontaneous emission ASE) entailing limited reabsorption of the lumi- nescence and eventual laser emission properties. Moreover, we use a polymerization method that allows for in situ polymerization of a conjugated polymer within a glass matrix [1]. The attractive features of the glass matrix include high dimensional stability, porous structure and good control ofthelayerthickness.Inthiswork,wereportonthechemistry, ®lm preparation, and ampli®ed spontaneous emission beha- vior of PTMPV blended with a glass matrix of a zirconium± organosilicon xerogel. As a further step towards a device realization, we validate a waveguide con®guration based on PTMPV polymer layer spun-coated over a silica groove. We report on the fabrication and characterization steps. 2. Chemistry and film preparation PTMPV was prepared via the water-soluble precursor method [2,3]. The process used for the preparation of the PTMPV/sol±gel glass composite is summarized schemati- cally in Fig. 1. The monomer used is an alkoxy derivative of polyphe- nylenevinylene) [4]. The polymer is formed in situ within the sol±gel matrix by polymerization under basic elimina- tion conditions. The polymer/glass composition is as follows: 10 ml of 70 wt.% zirconium tetrapropoxide in 1-propanol are mixed with 4 ml of glacial acetic acid. After stirring the solution for 30 min, 20 ml of 1-propanol is added following by dropwise addition of a solution of 12 ml of 2:1 glacial acetic acid/water. Then, 3.33 ml of 3-glycidoxypro- pyltrimethoxysilane is added. To 11.2 ml of the above- prepared solution, we then add 2 g of the PTMPV-salt and a further 20 drops of 2:1 glacial acetic acid/water mixture. At this point, the monomer is fully dissolved. Two ®lm types, samples numbers 1 and 2, are then prepared by dip- and spin- coating methods, respectively. After ®lm deposition, the samples are dried for 1 h at 408C. In situ polymerization of the monomers to form conjugated polymers is then accom- plished by using 13N aqueous NaOH as base, followed by washing cycles of a 1:1 mixture of glacial acetic acid/water and then methanol. Polymerization and washing steps are performedbydip-andspin-coatingmethods,respectively,for sample numbers 1 and 2. Film thickness, typically in the 1± 2 mm range, is controlled by the dip- and spin-coating con- ditions: speed, acceleration, and time. 3. Photo-luminescence characterization Films were ®rst characterized for their absorption and ¯uorescence spectra evidencing an enhanced gap between Synthetic Metals 124 2001) 59±61 * Corresponding author. Tel.: 33-1-47405554; fax: 33-1-47405567. E-mail address: donval@lpqm.ens-cachan.fr A. Donval). 0379-6779/01/$ ± see front matter # 2001 Elsevier Science B.V. All rights reserved. PII:S0379-677901)00422-2