In this work, we investigate the some main electrical and photocurrent properties of the Au/PVA(Co-doped)/n-Si diodes by using current-voltage (I-V) measurements at dark and various illumination intensity. Two types of diodes with and without polyvinyl alcohol (PVA) (Co-doped) polymeric interfacial layer were fabricated and measured at room temperature. Results show that the polymeric interfacial layers and series resistance (R-s) strongly affect the main electrical parameters of these structures. Also, metal/polymer/semiconductor (MPS) diode with PVA (Co-doped) interfacial organic layer is very sensitive to the light such that the current in reverse bias region increase by 10(3)-10(4) times with the increasing illumination intensity. The open circuit voltage V-oc and short-circuit current I-sc values of this MPS diode under 100 mW/cm(2) illumination intensity were found as 0.28 V and 19.3 mu A, respectively. (C) 2012 Elsevier B.V. All rights reserved.