Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Crystallite size


Synthesis and Fabrication of ZnO Nanorods on Silicon for Methanol Gas Sensor

Abdulqader D. Faisal; Mofeed A. Jaleel; Fahad Z. Kamal

Engineering and Technology Journal, 2019, Volume 37, Issue 3B, Pages 74-81
DOI: 10.30684/etj.37.3B.2

Zinc Oxide nanorods (ZnO NRs) were successfully synthesized via hydrothermal method. The growth process was conducted with seed layer concentration of 30 mM. The as-synthesized nanostructures were characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), and ultraviolet-visible (UV-VIS) spectrophotometer. The analysis results revealed a pure Wurtzite ZnO hexagonal nanostructures with preferred orientation (002) along c-direction. The calculated band gap and crystallite size are 3.2 eV and 53.18 nm respectively.  A methanol gas sensor was fabricated based on the annealed ZnO NRs on the silicon substrate. Optimized sensitivity at 250 ppm methanol vapor with fast response and recovery time was achieved. So, ZnO NRs film can serve as a good candidate for a methanol gas sensing device.

Effect of Deposition Temperature on Optical and Crystallographic Properties of CsI Thick Films Deposited using Spray Pyrolysis

J.H. Khulaef

Engineering and Technology Journal, 2017, Volume 35, Issue 2, Pages 195-203

A deposited layer of CsI has been prepared at different substrate
temperatures using spray pyrolysis technique. The X Ray diffraction of CsI
films reveals special pattern peaks (110), (200), (211), (220), (310) and (321).
From transmission spectra we calculated the energy gap of CsI films which
increase with increasing deposition temperature for direct transition is
estimated.