Au/PPy/n-Si Schottky barrier diodes (SBDs) were fabricated by forming polypyrrole (PPy) organic layer on n-Si using the spin coating technique. Frequency-dependent dielectric constant (epsilon'), dielectric loss (epsilon ''), loss tangent (tan delta), real and imaginary parts of electrical modulus (M' and M '') and AC electrical conductivity (sigma(ac)) parameters of the structure were investigated in the frequency range of 10-500 kHz. It was found that the values of the epsilon', epsilon '' and tan delta, in general, decrease with increasing frequency while an increase is observed in sigma(ac), M' and M ''. The tan delta and M '' also exhibit a peak at about zero-bias voltage, while peak intensity weakens with increasing frequency. The values of epsilon' and M' decrease with increasing voltage while an increase is observed in epsilon '', tan delta sigma(ac) and M ''. These changes in epsilon', epsilon '', tan delta, M', M '' and sigma(ac) values was attributed to surface charge polarization and the particular density distribution of surface states localized at PPy/n-Si interface.