To determine which of graphene (Gr) doping ratio (pure, 3-5%) into PVA is better or not, Gr-based PVA organic thin film were grown between Al/p-Si by using electro-spinning technique in same condition. For this purpose, both the voltage-dependent C and G/omega data were obtained at enough low and high two different frequencies (1 kHz and 500 kHz) for three different structures. Using the slope and intercept of C-2-V data, the electronic parameters [the doping-concentration atoms (N-A), the Fermi energy level (E-F), depletion layer width (W-d), and barrier-height (phi(B))] of the structures were calculated. The voltage-dependent profiles of interface-traps (D-it) and series resistance (R-s) were also extracted from the High-Low frequency capacitance and Nicollian-Brews method, respectively. Due to a special-distribution of D-it in the band gap of Si, the D-it-V plot for 5% Gr-doped PVA structure shows two distinctive peak as 8.60 x 10(13) eV(-1) cm(-2) at - 3.95 V and 9.70 x 10(12) eV(-1) cm(-2) at - 1.10 V, respectively. When these results were compared with each other; the W-d, E-F, and D-it values decrease with increasing rate of Gr-doped into PVA, whereas the BH increases. All results show that the best doping rate of Gr in to PVA is 5% and also (Gr:PVA) organic thin film should be successfully preferred instead of conventional insulators due to low cost/weight-D-it, high-BH, and easy production technique.