© 2019, The Minerals, Metals & Materials Society.Au/n-Si metal/semiconductor (MS) Schottky barrier diodes with and without (Ag2S-PVA) interlayer were prepared by the ultrasound-assisted method and their electric and dielectric properties were examined by using current–voltage (I–V) and capacitance–voltage (C–V) measuring devices. The structural, optical and morphological characteristics of the (Ag2S-PVA) were studied by x-ray diffraction (XRD), scanning electron microscopy (SEM) and UV–Visible spectroscopy. The observed peaks in the XRD pattern are related to the α-phase of silver sulfide. The UV–Visible spectrum of (Ag2S-PVA) shows the quantum confinement and SEM image proves the grain size in nano-scale. The ideality factor (n) and barrier height (BH) at zero bias (ΦB0(I–V)) were acquired from the I–V data. On the other hand; Fermi energy (EF), donor concentration atoms (ND), and BH (ΦB(C–V)) values were obtained from the reverse bias C–V data. The voltage-dependent resistance profile (Ln(Ri)–V) was obtained by applying Ohm’s law and also by the Nicollian–Brews methods. Also, considering the voltage-dependent n and BH, Nss–(Ec–Ess) profile was acquired from the forward biases I–V characteristics. Depending on high, intermediate and low biases ln(I)–Ln(V) curves have three linear regions with distinct slopes for MS and MPS structures. The predominant current-transport mechanisms were obtained in related regions via trap-charge limited current and space-charge limited current, respectively. These outcomes indicate that the (Ag2S-PVA) interlayer enhanced the performance of the diode considerably in terms of high rectifier rate (RR), shunt resistance (Rsh), and low surface states (Nss) and series resistance (Rs). Thus, the (Ag2S-PVA) interlayer can be used in MS type diode instead of a traditional insulator layer.