In this work we focus on heterojunction devices based on ruthenium phthalocyanine (RuPc)(2) and fullerene (C-60) molecular organic materials, useful for very low-cost photovoltaic applications. These materials show good performance in transport properties that can be easily modified and improved by doping process. Phthalocyanine absorption in the visible spectrum is helpful to extend C-60 absorption of the solar spectrum. Different thickness of both n-type C-60 and p-type (RuPc)(2) films have been experimented to evaluate compatibility between material properties to obtain better photovoltaic performances. Quantum efficiency and current voltage characteristics, both in the dark and in AM1.5G conditions, have been performed and discussed taking into account different environment conditions of samples preparation and storage. (C) 2003 Elsevier B.V. All rights reserved.