Scholar: Abdul Aziz Abdul Rehman Al-Muqhim Supervisor: Prof. Dr. Abdul Majid Department of Physics, College of Science Majmaah University (Zulfi Campus)

Optical studies of materials and their analysis are very promising and provide useful information about the properties of that material. We are intended to use the UV-Vis spectroscopy to explore the size of quantum structure of silver doped ZnO (ZnO:Ag) in different percentages of Ag in thin film form. Transmission or absorption spectra of material will be analyzed with some well known formula. Our results are in the range of 2.87 to 3.25 nm that shows doping concentration increase the size of quantum structure. Abstract Abstract

Introduction Introduction MOTIVATION: UV-Vis spectrometry the band gap and the size of the nanostructure Ag doped ZnO.

Methods & Materials MATERIALS: Silver doped ZnO (ZnO:Ag) in different percentages of Ag in thin film form on glass substrate are our target nanostructure made by dipping coating method. METHODS: The cut-off wavelength may be estimated from the intersection of the tangent line of the peak with the wavelength axis. This wavelength is used to determine the band gap of the ZnO:Ag where c is wavelength absorbed by the sample, and c is the speed of light. The size of nano structure (radius r )can be measured from the experimental UV-Vis absorption spectrum using the following expression derived from the effective mass model by using appropriate usual physical constants:

Methods & Materials Ultraviolet-Visible (UV) Spectrometer

Fig. 2 UV-Vis Absorbance Spectrum for ZnO:Ag and Pure ZnO nanostructured thin films with noisy range removed is shown dash lines shows the and touch the cut off wavelengths of each sample..

s: Sample # Name Percentage of Ag Cut of wave length Eg* (eV)Diameter (nm) 1 ZnO undoped 0% ZnO:Ag-44% ZnO:Ag-88% ZnO:Ag-1212% ZnO:Ag-1616% Using the cut off wavelength of each sample, band gap of ZnO:Ag and diameter are calculated for each sample, tabulated in the table. Table 1: Calculated results Eg and diameter of nano structures

The main objective of this work was to measure and obtain a UV-Vis spectrum of the ZnO:Ag samples then using the measured data calculate the band gap and Quantum (nano) structure size. This was achieved successfully after the UV-Vis spectrum was acquired. The spectrum was consistent with literature, and the Quantum (nano) structure size and band gap were measured easily from the spectrum, giving values that also agreed with literature and theory. Conclusion

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Acknowledgements We are thank full to the Department of Physics, College of Science, Majmaah University, and especially the Head of Department, Dean of the College of Science and Material Science Research (MSER) Group for the their help regarding the use of laboratory and research facilities.

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