Copper phthalocyanine (CuPc)/n-silicon junction was fabricated using thermal evaporator method. X-ray analysis of the CuPc film confirms the b-phase with preferred orientation along (100) direction. The crystallite size of the CuPc film was estimated using XRD data and observed to be about 12.6 nm. The current-voltage characteristics of Au/CuPc/n-Si/Au device was studied in dark and under illumination. The device showed diode characteristics. The diode parameters such as ideality factor, barrier height and series resistance were determined using different techniques such as conventional forward bias I-V characteristics, Cheung method and Norde’s function. A good agreement between the diode parameters calculated form these methods was observed. The analysis of the diode characteristics confirmed that the transport mechanism of the Au/CuPc/n-Si/Au diode at the higher electric fields was governed by the space-charge-limited currents. The photoconducting behavior of the diode suggests that it can be used as a photosensor in optoelectronic applications.