Doped Zinc Tin Research Articles

Controllable synthesis of Sn:ZnO/SnO2 nanorods: pH-dependent growth for an ethanol gas sensor

Tin-doped zinc oxide/tin oxide nanorod (Sn:ZnO/SnO2 NR) films were successfully synthesized using a solution immersion method by manipulating the pH concentration of the solutions to fabricate an ethanol gas sensor. Sn:ZnO/SnO2 NR films were prepared at constant Sn:ZnO solution pH (5.5), while the pH of the SnO2 solutions was varied between 4.5 and 6.5. In this study, the structural, morphological, and optical properties of Sn:ZnO/SnO2 NR films were investigated. The diameter and thickness of Sn:ZnO/SnO2 NR films were found to increase with the SnO2 pH. Interestingly, the Sn:ZnO/SnO2 NR sample that was prepared at SnO2 solution pH 5.5 showed the highest relative peak intensity along the c-axis plane orientation, which enhanced the sensor performance due to the shorter carrier pathway. In addition, this sample indicated a higher level of surface donor-related defects, which are favorable for sensing device performance. The samples were exposed to ethanol gas to measure their gas-sensing properties. Sn:ZnO/SnO2 NR films prepared at SnO2 solution pH 5.5 showed the highest sensing performance with short response/recovery times.

Electrical and Structural Properties of Nanostructured Tin Doped Zinc Oxide Deposited by Sol-Gel Immersion Method

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.

Electrical Properties of Tin-Doped Zinc Oxide Nanostructures Doped at Different Dopant Concentrations

This project has been focused on the electrical and optical properties respectively on the effect of Tin doped zinc oxide (ZnO) thin films at different dopant concentrations. These thin films were doped with different Sn dopant concentrations at 1 at%, 2 at%, 3 at%, 4 at% and 5 at% was selected as the parameter to optimize the thin films quality while the annealing temperature is fixed 500 oC. Sn doped ZnO solutions were deposited onto the glass substrates using sol-gel spin coating method. This project was involved with three phases, which are thin films preparation, deposition and characterization. The thin films were characterized using Current Voltage (I-V) measurement and ultraviolet-visible-near-infrared (UV-vis-NIR) spectrophotometer (Perkin Elmer Lambda 750) for electrical properties and optical properties. The electrical properties show that the resistivity is the lowest at 4 at% Sn doping concentration with the value 3.08 × 103Ωcm-1. The absorption coefficient spectrum obtained shows all films exhibit very low absorption in the visible (400-800nm) and near infrared (NIR) (>800nm) range but exhibit high absorption in the UV range.

Comparison of Characteristics of Fluorine Doped Zinc and Gallium Tin Oxide Composite Thin Films Deposited on Stainless Steel 316 Bipolar Plate by Electron Cyclotron Resonance-Metal Organic Chemical Vapor Deposition for Proton Exchange Membrane Fuel Cells

In order to replace the brittle graphite bipolar plates currently used for the PEMFC stack, coated SUS 316 was employed. As a metallic bipolar plate, coated SUS 316 can provide higher mechanical strength, better durability to shocks and vibration, less permeability, improved thermal and bulk electrical conductivity, as well as being thinner and lighter. To enhance the interfacial contact resistance and corrosion resistance of SUS 316, the deposition of GTO:F and ZTO:F composite films was carried out by ECR-MOCVD. The surface morphology of the films consisted of tiny elliptically shaped grains with a thickness of 1 microm. The corrosion current for GTO:F was 0.13 Acm(-2) which was much lower than that of bare SUS 316 (50.16 Acm(-2)). The GTO:F coated film had the smallest corrosion current due to the formation of a tight surface morphology with very few pin-holes. The GTO:F coated film exhibited the highest cell voltage and power density due to its lower ICR values.