Optical properties of double-layer structures consisting of Cu-phthalocyanine vacuum evaporated film and Langmuir-Blodgett film of pentadecyl-7,7,8,8-tetracyano-1,4-quinodimethane (pentadecyl-TCNQ) were investigated by ellipsometry and optical transmission. The obtained results indicate strong interaction between the materials; the resulting optical properties cannot be presented as the sum of those of the particular components. Two new effective absorption bands at 1.08 and 2.85 eV were found for such structures. The band at 2.85 eV coincides with a measured peak in photocurrent spectrum, which supports the idea on a charge transfer complex formation between Cu-phthalocyanine to TCNQ. (C) 2004 Elsevier B.V. All rights reserved.