Copper phthalocyanine-titanium oxide multilayers

Abstract

Copper phthalocyanine-titanium oxide (CuPc-TiOx) heteromultilayers have been fabricated by evaporation and reactive evaporation techniques, and their structural and optoelectronic properties investigated. X-ray diffraction and secondary ion mass spectroscopy confirm the formation of a clear alternating layered structure on a nanometer scale. An interface roughness of 7 Å has been achieved for a multilayer with an artificial period of 40 Å. Atomic force microscopy at scratched edges of the multilayers reveal double-layered structures of TiOx on CuPc, indicating the existence of two kinds of interface. Transverse photoconduction measurements on samples deposited on SnO2-coated glass, using a back electrode of Al, show the occurrence of electron transfer from CuPc to TiOx at the interfaces.