© 2020, Springer Science+Business Media, LLC, part of Springer Nature.There are several methods used to obtain the basic diode parameters that affect the diode quality of Schottky diodes (SD) such as ideality factor (n), barrier height (ΦBo), and series resistance (Rs). In this study, it is aimed to compare the results using Ohm’s law, Thermionic Emission theory (TE), Norde and Cheung-Cheung functions. The I–V measurement of the Au/7%Gr-doped PVA/n-GaAs type SD was taken in the range of 80–360 K in 20 K steps. Considering that each method is effective in the different voltage region of the I–V curve and the parameters are strongly voltage-dependent, the results are compatible with each other. Also, the interface states (Nss) were calculated with and without Rs for each temperature value, and it was attained that the effect of Rs reduced Nss values by almost 1 degree. This result reveals the importance of the Rs parameter for SDs. As a result, it is plainly represented that the basic diode parameters n, Rs and ΦBo values are strongly dependent on temperature and voltage, and affected by barrier inhomogeneity and surface states.