LANGMUIR-BLODGETT-FILMS CONTAINING CAROTENOID DYE .2. STRUCTURE AND CONDUCTING CHARACTERISTICS OF ETHYL BETA-APO-8-CAROTENOATE CADMIUM STEARATE LB FILMS

The structure, doping, and electrical conductivity characteristics of ethyl beta-apo-8-carotenoate dye (EA8C)/cadmium stearate Langmuir-Blod gett (LB) films were investigated. The EA8C/cadmium stearate mixed mul tilayer thin films, with the molar ratio of 1 : 4, prepared at subphas e pH 6, exhibited well-defined layered structures as determined by X-r ay diffraction (XRD) spectra. The mixed LB films went ready doping upo n exposure to iodine vapor or dipping in sulfuric acid solution. The U V/VIS and XRD data showed that the incorporated EA8C was thermally sta ble up to 80 degrees C. The best conductivity characteristics were obt ained with the iodine vapor. Thus, the mixed LB films exposed to iodin e vapor showed in-plane and transverse conductivities of 10(-6) and 10 (-7)-10(-8) S/cm, respectively. (C) 1997 John Wiley & Sons, Inc.