Phthalocyanine thin Films for Molecular Electronics

Phthalocyanine (Pc) thin films have been investigated with respect to their possible applications in molecular electronics. Samples of Pb-Pc and Er-diPc have been prepared by evaporation of purified substances in high vacuum. Within the monoclinic phase of Pb-Pc there is a field-induced quasimolecular switching between states of different electrical conductivity. Using Pb-Pc as active material a field effect transistor has been developed. This substance can also be used for a highly specific NO2-sensor. Electrochromic behaviour is exhibited by rare earth-diPcs. Using ErH(Pc)2 an electrochromic cell switching between green, red and blue/violet color has been investigated. As a hopeful step towards molecular engineering nanometer structures can be created by scanning tunneling microscopy. We have been able to create straight lines of only a few nanometers thickness by chemical decomposition in a Pb-Pc thin film.