The effect of Mo-doped and undoped PVC+TCNQ interfacial layer on electrical characteristics of a Au/PVC+TCNQ/p-Si structure was investigated using current-voltage (I-V), capacitance-voltage (C-V) and conductance-voltage (G/omega-V) measurements at room temperature. The energy dependent interface states density (N-ss) was obtained from the forward bias I-V data by taking into account voltage dependent effective barrier height (Phi(e)) for two diodes,. i.e. with and without Mo doping. The voltage dependent resistance (R-i) of structures was also obtained using Ohm's law and the method of Nicollian and Brews for the diodes. In order to eliminate the effect of series resistance (R-s), C and G/omega at high frequency values were corrected. N-ss and R-s values were compared between the diodes and experimental results showed that N-ss and R-s values of the Mo-doped PVC+TCNQ structure are considerably lower than those of the undoped PVC+TCNQ structure. The other important parameters such as ideality factor (n), reverse saturation current (I-s), zero-bias barrier heights (Phi(B0)) and R-s were obtained from forward bias I-V data by using I-V, Cheung and Norde methods. Experimental results confirmed that the Mo-doped (PVC+TCNQ) layer considerably improved the performance of the Au/PVC+TCNQ/p-Si structure. (C) 2015 Elsevier Ltd. All rights reserved.