An Al/methyl violet (MV)/n-Si/AuSb Schottky structure was fabricated and its current-voltage (I-V), capacitance-voltage (C-V) and capacitance-frequency (C-f) characteristics were investigated at room temperature. A modified Norde's function combined with conventional forward I-V method was used to extract the parameters including barrier height (BH) and series resistance. The BH and series resistance obtained from Norde's function have been compared with those from Cheung functions, and it was seen that there is good agreement between the BH values from both methods. It was also seen that the values of capacitance are almost independent of frequency up to a certain value of frequency, whereas at high frequencies the capacitance decreased. The higher values of capacitance at low frequencies were attributed to the excess capacitance resulting from the interface states in equilibrium with the n-Si that can follow the alternating current (ac) signal.