Nowadays, the organic base solar cell has attracted a lot of interests due to its potential as a low cost solar cell. This paper investigates the potential of the organic material which is copper phthalocyanine (CuPc) as the p-type organic material in the solar cell. The CuPc films have been prepared by spin coating technique on Si-n substrate. The optical properties of CuPc thin film were studied using the UV-Vis-NIR spectrometer in the spectral range 300-800 nm. The CuPc was grown on the glass substrate to study the optical properties. The band gap of the films has been calculated directly from the data plotted. The best properties of CuPc thin film was used to develop an organic / inorganic : Al / Si-n / CuPc / Ag solar cell. The electrical property which is I-V characterization shows the performance and the efficiency of the cell due to the film thicknesses.