Optical and dielectric properties of electrochemically deposited p-Cu₂O films

A perfect crystalline phases of cuprous oxide were synthesized using electrochemical method at different duration ( 15, 30 and 60 min). The deposited samples were examined by XRD, SEM, UV–Vis absorption and Mott-Schottky measurements. The effect of the deposition time on the optical and dielectric properties of Cu₂O was studied in detail. The x-ray diffraction indicated increasing of crystallinity and crystallite size with increasing of deposition time. SEM micrographs exhibited grains with three-faced pyramid shape and grains size increased with improvement of crystallinity. Optical study is performed to calculate optical band gap (E_g), absorption coefficient (α), extinction coefficient (k), refractive index (n), dielectric constants (ε), urbach energy (E_U) and optical conductivity (σ _opt) using the transmittance and absorption spectra in the wavelength range of 400–1100 nm. Among all grown samples, the film deposited at 60 min shows interesting optical and dielectric properties. The Mott-Schottky analysis shows that the film deposited at 60 min has a low carrier density compared to samples deposited in other deposition times. (paper)