Papers by Author: Salman A.H. Alrokayan

Abstract: In this work, seeded porous silicon (PSi) was used as a substrate in the growth of ZnO nanostructures. PSi was prepared by electrochemical etching method. ZnO thin films as seeded were deposited via sol-gel spin coating method. ZnO nanostructures were grown on seeded PSi using hydrothermal immersion method. In order to study the effect of post-heat treatment on the substrate, post annealing temperature were varied in the range of 300 to 700 °C. The FESEM results shows ZnO thin film composed of nanoparticles were distributed over the PSi surface. Based on AFM characterization, the smoothest surface was produced at post annealing temperature of 500 °C. There are two different peaks appeared in PL characterization. The peak in near-UV range is belonging to ZnO thin films while a broad peak in visible range can be attributed to ZnO defects and PSi surface. In addition, FESEM, XRD and PL were used to characterize the ZnO nanostructures. The FESEM results revealed ZnO nano-flower were successfully grown on seeded PSi. Hexagonal wurtzite of ZnO with dominated by the plane (100), (002), and (101) was found by XRD characterization. Two different peaks in UV range and visible range can be attributed to ZnO nano-flower and various defects of ZnO, respectively.

Abstract: Tin-doped Zinc Oxide (Sn-doped ZnO) thin films were prepared using zinc acetate dehydrate as a starting material by sol-gel immersion method. The doping concentrations were varied at 0 at.%, 1.0 at.%, 2.0 at.% and 3.0 at.%. The synthesized samples were characterized by Field Emission Scanning Electron Microscopy (FESEM).

Abstract: Tin-doped Zinc Oxide (Sn-doped ZnO) thin films were prepared using zinc nitrate hexahydrate as a starting material by sol-gel immersion method. The synthesized samples were characterized by current-voltage (I-V) measurement and Field Emission Scanning Electron Microscopy (FESEM). The Sn doping concentration were varied at 1.0 at.%, 2.0 at.%, 3.0 at.% and 4.0 at.%. FESEM images show that as the Sn concentration increased, the nanoparticles size of Sn-doped ZnO become denser and less grain boundary which might help in improvement of the electrical properties.

Abstract: Tin-doped Zinc Oxide (Sn-doped ZnO) thin films were prepared using zinc nitrate hexahydrate as a starting material by sol-gel immersion method. Then the synthesized samples were characterized by current-voltage (I-V) measurement and FESEM. The Sn doping concentration were varied at 0.2 at.%, 0.4 at.%, 0.6 at.%, 0.8 at.% and 1.0 at.%. The result suggests that the optimum value for Sn doping concentration was 0.8 at.% which exhibited the highest conductive sample with value of 3.00 ×10^-6 S/cm.

Abstract: Tin-doped Zinc Oxide (Sn-doped ZnO) thin films were prepared using zinc acetate dehydrate as a starting material by sol-gel immersion method. The doping concentrations were varied at 0 at.%, 0.5 at.%, 1.0 at.%, 2.0 at.%, 3.0 at.% and 4.0 at.%. The synthesized samples were characterized by current-voltage (I-V) measurement and UV-VISS spectrometer.

Abstract: Sol gel immersion method has been used to synthesize magnesium doped zinc oxide (Mg:ZnO) thin film on glass substrate. The morphological of annealed thin film was study using atomic force microscopy (AFM) while UV-Visible spectroscopy was used to examine the optical transmittance properties. The optical band gap was estimated by using Tauc’s method. From the results, the surface roughness was change as annealing temperature increases. The increasing of annealing temperature also affects the transmittance spectra which are shifted to lower wavelength. The optical band gaps of the thin film were varied due to different annealed temperature.