© 2019 Elsevier B.V. The copper selenide (CuSe) nanostructures with different pH values are prepared by an ultrasound-assisted technique. The spectroscopic, morphological and structural characteristics of prepared nanomaterials were investigated via different methods. The XRD patterns depicted that the samples have crystalline structures. HRTEM images show the nanostructures size and it also showed that the morphology changed with changing pH value. FT-IR Spectroscopy confirmed the formation of CuSe and evaluates the changes induced by pH variation and in the energy variation between functional groups. Diffuse reflectance spectroscopy (DRS) results demonstrate the absorption regions of CuSe nanostructures are 300–400 nm. Some electrical parameters of the manufactured Au/(CuSe-PVA)/n-Si Schottky barrier diodes (SBDs) were obtained from the impedance measurements (capacitance/conductance-voltage) in the frequency range between 10 kHz and 1 MHz. The amounts of capacitance (C) and conductance (G/ω) were found as are strongly frequency and voltage dependent. While the values of depletion layer width (W d ) and barrier height (Φ B (C-V)) increase with increasing frequency, the concentration of donor atoms (N D ) decreases. Both the voltage-dependent profile of surface states (N ss ) and series resistance (R s ) were measured and estimated using the low-high frequency capacitance and Nicollian-Brews methods, respectively. These results showed a distinctive peak in the depletion region because of the spatial distribution of the N ss between (CuSe-PVA) and n-Si in the band-gap of Si. Obtained results indicated that the N ss , R s , and interfacial (CuSe-PVA) layer are significant parameters for the electrical properties.