The phthalocyanine molecules are unique with respect to structural, electrical and optical properties. Due to their intense colour, and high thermal and chemical stability, phthalocyanines were firstly employed as green and blue colorants in photographic, printing, plastic and textile industries. A metal free phthalocyanine molecule H2Pc and metal phthalocyanine such as CuPc, ZnPc contains four chelate six member rings. The coordination and covalent coordination of the central metal atoms explain the unusual stability of these atoms in the phthalocyanine molecule. We have studied the IR spectroscopy to see the structural differences between different phthalocyanines used in this paper. In H2Pc, ZnPc and CuPc there is little difference in optical and structural properties however the solar cells made of these materials give different performances, which suggests that the physical properties have great effect on the devices performance determination.

Keywords: H₂Pc, CuPc, ZnPc, Structural Properties, Photovoltaic Cells.