Au/n-GaAs structures with polyvinyl alcohol (PVA) organic interface layer were produced by doping graphene (Gr) and zinc (Zn) separately to the interface layer. The electrical characterizations of both structures which have Schottky barrier diodes (SBDs) property were compared both at the forward and reverse biases at room temperature using the current-voltage (I-V) data. For this purpose, the main electrical parameters such as saturation current (I-o), barrier height (Phi(Bo)), ideality factor (n), series (R-s) resistance, and shunt (R-sh) resistance are obtained for Gr doped and Zn doped Au/PVA/n-GaAs and compared by utilizing thermionic emission theory, Cheung's method and modified Norde's methods. Investigation of Rs and Rsh values at (+/- 2 V) for Gr-doped and Zn-doped structures ensured to obtain the rectifiying ratio values and give an idea to find out the better quality of these structures. Thus, the results for the comparison of polymer interlayers with different dopants show that doping with both Zn and Gr differently improved the quality of SBDs when considering the main electrical parameters.