To investigate the effect of 2% graphene cobalt (GC)-doped (Ca3Co4Ga0.001Ox) interfacial layer on the main electrical parameters, Au/n-Si (MS) Schottky barrier diodes (SBDs) were fabricated with and without this inter-facial layer. Using forward and reverse bias current-voltage (I-V) measurements, selected electrical parameters of these diodes were obtained and compared at room temperature. The energy density distribution profiles of the surface states (N) were obtained from the forward-bias I-V data by taking into account the voltage-dependent effective barrier height (be) and ideality factor (n(V)). The value of Ns, for the MPS-type diode is one order of magnitude lower than that of the MS diode. These results indicated that the 2% GC-doped (Ca(3)Co(4)Oa(0.001)O(x)) interfacial layer prevents reaction and inter-diffusion between Au and n-Si as well as passivating the active dangling bonds at the semiconductor surface. In addition, the voltage-dependent profile of the resistance (11,) was also obtained for the two diodes from the I-V data using Ohm's law. In both the MS- and MPS-type diodes, an apparent exponential increase in hl was observed from the mid-gap toward the bottom of the E. The experimental results show that the existence of Nss, Rs, and the interfacial layer has a great effect on the electrical characteristics of these structures. The value of the depletion layer width was obtained from C-V measurements at 300 kHz for the two diodes. The obtained results show that the GC-doped (Ca3Co4Ga0.001Ox) interfacial layer considerably enhances the diode performance. (C) 2015 Elsevier B.V. All rights reserved.