Synthesis, optical and AC electrical characteristics of nanocomposites (Bi2O3/ZnO) films prepared by thermal evaporation technique

Abstract

In this paper, pure bismuth oxide (Bi2O3) and ZnO-doped with a ratio of (0, 0.12, 0.24, 0.36 and 0.48 wt.%) thin films are prepared by thermal evaporation methods under pressure 1×10-7 bar with a rate of deposition 0.5 nm.s-1 , at ambient temperature on glass substrates (RT) with thickness 50 nm and annealed at temperature 573 K for 2 hours. The phase structures of Bi2O3 (monoclinic) and Bi2O3/ZnO NCPs are confirmed by X-ray diffraction (XRD) investigation. The concentration of ZnO-doping reduces the average crystallite size from 17,35 nm to 8.67 nm. Moreover, using XRD data, the average strain, stress, and dislocation density values are computed. The spectroscopy techniques such as Fourier transform infrared (FT-IR) and scanning electron microscopy with field emission probes were used to examine the structures. The FT-IR results showed no chemical interactions between the (Bi2O3/ZnO) NPs. The results of the field emission-scanning electron microscope (FE-SEM) analysis the (Bi2O3/ZnO) NPs were distributed uniformly throughout. The actually result of optical characteristics for (Bi2O3/ZnO) showed that the absorbance, and absorption coefficient, increase with the increased concentrations of (ZnO). At the same time, the transmittance and energy band gaps were decreased with a rise in concentrations (ZnO) that have a high ability to absorb UV-light. The dielectric characteristics were checked in the frequency range from 100 Hz to 5 MHz. The results of the insulating characteristics showed that the dielectric constant and the dielectric loss of thin films (Bi2O3/ZnO) decreased with increasing frequency. In contrast, they increase when the concentration of (ZnO NPs) increases. The A.C conductivity of the thin films (Bi2O3/ZnO) increases with the frequency and concentration of (ZnO) NPs. Finally, the structural and insulating results the indicated characteristics of the (Bi2O3/ZnO) thin films may be helpful in various nano-electronic devices and sensors.