Semiconductor oxide for gas sensing applications

The semiconductor metal oxide oxygen sensors have received the most attention during the past few years due to their advantages of low cost, small size, simple structure, and the ease of integration. In this project, SrTi1−x FexO3−δ (STFx, 0 ≤ x ≤ 1) was used as the material for oxygen sensing appli...

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Main Author: Ang, Wan Chia
Other Authors: Tan Ooi Kiang
Format: Final Year Project
Language:English
Published: 2010
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Online Access:http://hdl.handle.net/10356/39574
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-395742023-07-07T16:23:25Z Semiconductor oxide for gas sensing applications Ang, Wan Chia Tan Ooi Kiang School of Electrical and Electronic Engineering DRNTU::Engineering::Electrical and electronic engineering::Control and instrumentation::Control engineering The semiconductor metal oxide oxygen sensors have received the most attention during the past few years due to their advantages of low cost, small size, simple structure, and the ease of integration. In this project, SrTi1−x FexO3−δ (STFx, 0 ≤ x ≤ 1) was used as the material for oxygen sensing application. The STFx thin films and composite films were developed by using modified sol-gel spin-coating technique. STFx sol-gel solutions with varying iron content were prepared and examined prior to deposition of STFx thin films and composite films. Effects of sol molarity, water content, and amount of PVP added into the STFx sol-gel solutions were studied and investigated in order to obtain stable solution and uniform spin-coated thin films. The surface morphology of the spin-coated thin films was characterized using FESEM and AFM. Next, the effect of annealing temperature on thin film grain size and crystallization was studied using XRD and the optimum annealing temperature was chosen for gas sensing device fabrication. On the other hand, STF02 composite films were obtained by dispersing the STF02 nanoparticles in STF02 sol-gel solutions. STF02 nanoparticles were synthesized using high energy ball milling technique. Particle size and dispersion of STF02 nanoparticles were then investigated using Zeta sizer test. Slurry preparation procedure was revised to obtain stable and well dispersed STF02 slurry. The STF02 sol-gel solution recipe for slurry preparation was modified by adding PVP in order to reduce cracks formation. The optimum amounts of PVP and powder-to-sol weight ratios were investigated to obtain crack-free composite film. Surface morphology of the spin-coated composite films was studied using SEM. In gas sensing device fabrication process, STF04 thin film was spin-coated onto the SiO2 wafer substrate with gold bottom interdigitated electrodes and patterned using photolithography technique. Next, gas sensing characterization was carried out by using home-designed gas sensor characterization system (GSCS). The STF04 gas sensing devices showed excellent oxygen sensing response. The annealing temperature and PVP addition effect on the devices sensing response were characterized and evaluated. Bachelor of Engineering 2010-05-31T07:52:24Z 2010-05-31T07:52:24Z 2010 2010 Final Year Project (FYP) http://hdl.handle.net/10356/39574 en Nanyang Technological University 82 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Engineering::Electrical and electronic engineering::Control and instrumentation::Control engineering
spellingShingle DRNTU::Engineering::Electrical and electronic engineering::Control and instrumentation::Control engineering
Ang, Wan Chia
Semiconductor oxide for gas sensing applications
description The semiconductor metal oxide oxygen sensors have received the most attention during the past few years due to their advantages of low cost, small size, simple structure, and the ease of integration. In this project, SrTi1−x FexO3−δ (STFx, 0 ≤ x ≤ 1) was used as the material for oxygen sensing application. The STFx thin films and composite films were developed by using modified sol-gel spin-coating technique. STFx sol-gel solutions with varying iron content were prepared and examined prior to deposition of STFx thin films and composite films. Effects of sol molarity, water content, and amount of PVP added into the STFx sol-gel solutions were studied and investigated in order to obtain stable solution and uniform spin-coated thin films. The surface morphology of the spin-coated thin films was characterized using FESEM and AFM. Next, the effect of annealing temperature on thin film grain size and crystallization was studied using XRD and the optimum annealing temperature was chosen for gas sensing device fabrication. On the other hand, STF02 composite films were obtained by dispersing the STF02 nanoparticles in STF02 sol-gel solutions. STF02 nanoparticles were synthesized using high energy ball milling technique. Particle size and dispersion of STF02 nanoparticles were then investigated using Zeta sizer test. Slurry preparation procedure was revised to obtain stable and well dispersed STF02 slurry. The STF02 sol-gel solution recipe for slurry preparation was modified by adding PVP in order to reduce cracks formation. The optimum amounts of PVP and powder-to-sol weight ratios were investigated to obtain crack-free composite film. Surface morphology of the spin-coated composite films was studied using SEM. In gas sensing device fabrication process, STF04 thin film was spin-coated onto the SiO2 wafer substrate with gold bottom interdigitated electrodes and patterned using photolithography technique. Next, gas sensing characterization was carried out by using home-designed gas sensor characterization system (GSCS). The STF04 gas sensing devices showed excellent oxygen sensing response. The annealing temperature and PVP addition effect on the devices sensing response were characterized and evaluated.
author2 Tan Ooi Kiang
author_facet Tan Ooi Kiang
Ang, Wan Chia
format Final Year Project
author Ang, Wan Chia
author_sort Ang, Wan Chia
title Semiconductor oxide for gas sensing applications
title_short Semiconductor oxide for gas sensing applications
title_full Semiconductor oxide for gas sensing applications
title_fullStr Semiconductor oxide for gas sensing applications
title_full_unstemmed Semiconductor oxide for gas sensing applications
title_sort semiconductor oxide for gas sensing applications
publishDate 2010
url http://hdl.handle.net/10356/39574
_version_ 1772829088700956672