Conducting polycrystalline layers in polymer composites have been prepared by a two step reticulate doping technique i.e. by exposing solid solution of bis(ethylenedithiotetrathia)fulvalene (BEDT-TTF) in the polymer matrix to vapours of solvent containing I-2 or IBr. Characterisation of trihalide anion mixtures in the obtained layers of BEDT-TTF salts was completed by low frequency Raman spectroscopy. The surface morphology and the chemical composition of the layers were investigated by means of scanning electron microscopy with energy dispersive X-ray microanalysis and atomic force microscopy.