The electrical and interface state properties of Au/perylene-monoimide (PMI)/n-Si Schottky barrier diode have been investigated by current-voltage (I-V) and capacitance-voltage (C-V) measurements at room temperature. A good rectifying behavior was seen from the I-V characteristics. The series resistance (R-s) values were determined from I-V and C-V characteristics and were found to be 160 U and 53 U, respectively. The barrier height (Phi(b)) of Au/PMI/n-Si Schottky diode was found to be 0.694 eV (I-V) and 0.826 eV (C-V). The ideality factor (n) was obtained to be 4.27 from the forward bias I-V characteristics. The energy distribution of interface state density (N-ss) of the PMI-based structure was determined, and the energy values of Nss were found in the range from E-c - 0.508 eV to E-c - 0.569 eV with the exponential growth from midgap toward the bottom of the conduction band. The values of the Nss without Rs are 2.11 x 10(12) eV(-1) cm(-2) at E-c - 0.508 eV and 2.00 x 10(12) eV(-1) cm(-2) at E-c - 0.569 eV. Based on the above results, it is clear that modification of the interfacial potential barrier for metal/n-Si structures has been achieved using a thin interlayer of the perylene-monomide. (C) 2012 Elsevier B.V. All rights reserved.