In this study, the reduced graphene oxide (rGO) was synthesized from graphene oxide (GO) by using chemical reduction method. The spray pyrolysis technique was used to deposit rGO film on n-InP substrate. The structural, morphological, and optical properties of rGO film were investigated by XRD, SEM, and UV–Vis spectroscopies. Au/rGO/n-InP device was fabricated and the current–voltage characteristics were examined in the temperature range of 60–300 K. The device parameters of barrier height (BH) and ideality factor are found to be strong functions of temperature due to the barrier inhomogeneities at metal–semiconductor interface. The temperature dependency of the electrical characteristics of the Au/rGO/n-InP SBD was explained by the thermionic field emission (TFE) theory with Gaussian distribution (GD) of the BH values. The BH has a GD with a mean barrier height of $$\overline{\Phi }_{bo}$$ = 0.93 eV between 120 and 300 K temperatures and $$\overline{\Phi }_{bo}$$ = 0.62 eV between 60 and 120 K temperatures. It was seen that the existing current mechanism is predominantly controlled by space-charge-limited current (SCLC) at large forward bias according to the sample temperature. The rGO interface plays also an important role in the conduction mechanism and electronic properties of the device.