| dc.description.abstract | Dopants are used to modify the properties of metal oxides. They are classified into p type and ntype. The p type dopants are electron acceptors and they reduce the bandgap energy. The n- type dopants are electron donors. Ag+ have two characteristics features such that they can be used in place of substitution and interstitial. Citrus reticulata capped silver doped zinc oxide nanoparticles (AgZnONPs) were synthesized via chemical precipitation method, with Citrus reticulata acting as capping, reducing and stabilizing agents. The nanoparticles were synthesized at different doping concentrations of silver (Agx-ZnO) (x=0.1, 0.25, 0.5, 0.75, 1.0, 1.5, and 2.0 %). The effects of different dopant concentration on structural and optical properties of Citrus reticulata capped ZnO nanoparticles were investigated using X-ray diffraction (XRD), Ultra Violet- Visible spectrophotometer (UV-Vis), Fourier transform Infrared spectroscopy (FT-IR) and Photoluminescence (PL) spectroscopy. The XRD pattern obtained showed that hexagonal wurzite structure of ZnO nanoparticles was retained on addition of Ag as a dopant. 0.1% Ag-ZnO displayed highest peak in XRD pattern at plane [101]. The crystal size of the nanoparticles ranged from 15.2919.87nm. At 0.5% Ag-ZnONPs, the XRD peak shifted to higher 2 theta degrees compared to other doping concentrations. The bandgap energies of Ag-ZnONPs were estimated using Tauc’s plot. The bandgap energies were observed to decrease with increase in Ag doping concentration. 0.25% AgZnONPs had a bandgap energy of 3.69eV and that of 2.0% had a bandgap energy of 3.03eV. FT-IR spectra showed absorption in both functional group and fingerprint regions. The absorption band between 420- 470cm-1 is associated with that of the metal oxide. The PL spectrum showed emission at a wavelength of 350- 500nm. The optical properties predict the possibility of using of Ag-ZnONPs in solar cells and optoelectronics. | en_US |
