Dielectric Properties of SnO2 Thin Film Using SPR Technique for Gas Sensing Applications
06 May 2014-Vol. 2014, pp 1-4
TL;DR: In this article, the surface plasmon resonance (SPR) response of bilayer film was fitted with Fresnel's equations in order to calculate the dielectric constant of SnO2 thin film.
Abstract: Focus has been made on the determination of dielectric constant of thin dielectric layer (SnO2 thin film) using surface plasmon resonance (SPR) technique and exploiting it for the detection of NH3 gas. SnO2 thin film has been deposited by rf-sputtering technique on gold coated glass prism (BK-7) and its SPR response was measured in the Kretschmann configuration of attenuated total reflection using a p-polarised light beam at 633 nm wavelength. The SPR response of bilayer film was fitted with Fresnel’s equations in order to calculate the dielectric constant of SnO2 thin film. The air/SnO2/Au/prim system has been utilized for detecting varying concentration (500 ppm to 2000 ppm) of NH3 gas at room temperature using SPR technique. SPR curve shows significant shift in resonance angle from 44.8° to 56.7° on exposure of fixed concentration of NH3 gas (500 ppm to 2000 ppm) with very fast response and recovery speeds.
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TL;DR: In this paper, a room temperature (22°C) operated gas sensor using the optimized Long Range Surface Plasmons (LRSPs) configuration was developed for detecting NO2 gas in a broad concentration range from 0.5 ppm to 2000 ppm.
Abstract: Long Range Surface Plasmons (LRSPs) are excited in the SnO2/Au/SnO2/prism structure using Kretschmann configuration for detecting NO2 gas. SnO2 thin films of two different thicknesses are grown by RF sputtering technique and 205 nm thin SnO2 film resulted in the sharp LRSP resonance (LRSPR) reflectance curve with the minimum reflectance (Rmin) = 0.05 at the resonance angle (θspr) of 42.38°. LRSPR based room temperature (22 °C) operated gas sensor using the optimized SnO2/Au/SnO2/prism configuration is developed in the present work for effectively detecting NO2 gas in a broad concentration range from 0.5 ppm to 2000 ppm. The LRSPR reflectance curve corresponding to the prepared sensor shows an appreciable shift of 8.47° in the resonance angle on exposure to NO2 gas (2000 ppm). The developed optical sensor illustrated high sensitivity (0.2°/ppm) along with the limit of detection (LOD) of 0.38 ppm of NO2 gas. The sensor exhibited outstanding selectivity towards NO2 gas and showed insignificant response to various other interfering gases. The obtained results highlight the successful fabrication of competent LRSPR based optical gas sensor capable of detecting NO2 gas at room temperature.
25 citations
TL;DR: This work establishes a general experimental methodology for studying localized charge transfer at the molecular scale that is applicable to other photoactive nanoscale systems.
Abstract: Layered indium selenide (InSe) is an emerging two-dimensional semiconductor that has shown significant promise for high-performance transistors and photodetectors. The range of optoelectronic appli...
13 citations
TL;DR: In this paper, the authors used a scanning electron microscope (SEM) with an energy-dispersive spectrometer (EDX) to determine the topography of PVP/SnCl4 nanofibrous mats.
Abstract: The aim of this paper was to prepare SnO2 nanowires using electrospinning and calcination processes from a poly(vinylpyrrolidone), dimethylformamide, ethanol and tin(IV) chloride pentahydrate solution. The composite PVP/SnCl4 nanofibers obtained via electrospinning method were dried and calcined in a vacuum to remove the polymer matrix at a temperature of 500 °C for 10 h. Three types of nanowires with a polymer to precursor ratios of 2:1, 1:1, 1:3 were produced. The morphology and chemical composition of as-spun PVP/SnCl4 nanofibers and SnO2 nanowires obtained after heat treatment were carried out using a scanning electron microscope (SEM) with an energy-dispersive spectrometer (EDX). The Fourier-transform infrared spectroscopy (FTIR) spectra of the prepared nanomaterials were also investigated. To determine the topography of PVP/SnCl4 nanofibrous mats, an atomic force microscope (AFM) was used. A 100-fold measurement of the nanowire size showed that, depending on the amount of precursor in the spinning solution, nanowires with diameters ranging from 20 to 260 nm were obtained. The optical property analysis was performed on the basis of absorbance spectra recorded over UV–Vis spectral range. The complex refractive index n and complex dielectric permeability e of obtained tin oxide nanowires were determined as a function of the radiation energy. Depending on the precursor content in spinning solution, the one-dimensional SnO2 nanostructures were characterised by a refractive index in the range of 1.51–1.56, whereas the dielectric constant ranged from 2.26 to 2.30. The optical properties and the structure of one-dimensional SnO2 nanomaterials allow to use this type of materials in the construction of novel type photovoltaic cells and electronic devices.
6 citations
TL;DR: In this article, X-ray diffraction and scanning electron microscopy showed that the films are nanocrystalline and the transmittance of the films was measured at room temperature in the wavelength range 290-1100nm, which was in turn used to deduce the optical parameters, such as the extinction coefficient, refractive index, real and imaginary parts of the dielectric constant, and energy loss.
Abstract: SnO2 thin films are usually used as fore contacts in superstrate thin film solar cells such as thin film CdS/CdTe solar cells. Doping SnO2 with fluorine improves its electrical properties and increases its optical bandgap energy besides improving other optical parameters. SnO2:F thin films of thickness around 200 nm were deposited on glass substrates by the spray pyrolysis method at a substrate temperature Ts = 480°C. X-ray diffraction and scanning electron microscopy showed that the films are nanocrystalline. The transmittance of the films was measured at room temperature in the wavelength range 290–1100 nm, and used to calculate the reflectance, which was in turn used to deduce the optical parameters, such as the extinction coefficient, refractive index, real and imaginary parts of the dielectric constant, and energy loss. The relationships between these parameters and photon energy were investigated and compared with the results obtained by other authors.
5 citations
References
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Book•
03 May 1988
TL;DR: In this article, surface plasmons on smooth surfaces were used for light scattering at rough surfaces without an ATR device, and surface plasmon on gratings for enhanced roughness.
Abstract: Surface plasmons on smooth surfaces.- Surface plasmons on surfaces of small roughness.- Surfaces of enhanced roughness.- Light scattering at rough surfaces without an ATR device.- Surface plasmons on gratings.- Conclusions.
4,890 citations
TL;DR: In this article, a new method of exciting nonradiative surface plasma waves (SPW) on smooth surfaces, causing also a new phenomena in total reflexion, is described.
Abstract: A new method of exciting nonradiative surface plasma waves (SPW) on smooth surfaces, causing also a new phenomena in total reflexion, is described. Since the phase velocity of the SPW at a metal-vacuum surface is smaller than the velocity of light in vacuum, these waves cannot be excited by light striking the surface, provided that this is perfectly smooth. However, if a prism is brought near to the metal vacuum-interface, the SPW can be excited optically by the evanescent wave present in total reflection. The excitation is seen as a strong decrease in reflection for the transverse magnetic light and for a special angle of incidence. The method allows of an accurate evaluation of the dispersion of these waves. The experimental results on a silver-vacuum surface are compared with the theory of metal optics and are found to agree within the errors of the optical constants.
2,707 citations
"Dielectric Properties of SnO2 Thin ..." refers background in this paper
...There are two configurations for exciting surface plasmon (SP) wave at the metal-dielectric interface: one is Otto configuration [2] and the other is Kretschmann [3] configuration....
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Book•
15 Apr 1994
TL;DR: In this article, the Stannic Oxide Sensor as a Combustion Monitor is described and the performance of the Tin Dioxide Ceramic Sensor is evaluated. But the performance is not as good as the one described in this paper.
Abstract: Introduction. Fabrication of the Stannic Dioxide Ceramic Sensor. The Performance of the Tin Dioxide Ceramic Sensor. Sensitivity Modification Using Additives. Selectivity. The Stannic Oxide Sensor as a Combustion Monitor. The Domestic Gas Alarm. Industrial Gas Sensors and Instrumentation. Future Developments. Appendix: Testing and Characterization.
340 citations
"Dielectric Properties of SnO2 Thin ..." refers result in this paper
...8 corresponding to planes (110), (101), and (211) planes of SnO 2, respectively are in good agreement to the reported values for rutile structure [7], confirming the formation of polycrystalline SnO 2 thin film....
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TL;DR: In this article, a three-interface surface plasmon resonance (SPR) geometry with the "angular interrogation" approach is discussed, and the effect of thermal changes on the SPR curve through numerical simulations is studied.
Abstract: We present a detailed discussion of the three-interface surface plasmon resonance (SPR) geometry with the "angular interrogation" approach, and study the effect of thermal changes on the SPR curve through numerical simulations. An optical temperature sensor based on SPR, which has been shown to be a promising method to be used in the development of chemical, physical, and biomedical sensors, is proposed. The temperature sensor employs a three-interface SPR geometry where the layer making the interface with the environment has a refractive index highly sensitive to the changes in the temperature of the environment. The resolution of the temperature measurement is dependent on the angular resolution of the detection system and the temperature sensitivity of the sensing layer. The comparison of thermal sensitivities of three and two-interface SPR geometries is also presented.
187 citations
TL;DR: In this paper, the effect of growth pressure on the surface morphology and structural property of SnO2 film was studied using Atomic force microscopy (AFM), Scanning electron microscopy and X-ray Diffraction (XRD) respectively.
Abstract: Semiconducting SnO2 thin films having higher value of electrical conductivity have been deposited using RF sputtering technique in the reactive gas environment (30% O2 + 70% Ar) using a metallic tin (Sn) target for detection of oxidizing NO2 gas. The effect of growth pressure (12–18 mTorr) on the surface morphology and structural property of SnO2 film was studied using Atomic force microscopy (AFM), Scanning electron microscopy (SEM) and X-ray Diffraction (XRD) respectively. Film deposited at 16 mTorr sputtering pressure was porous with rough microstructure and exhibits high sensor response (∼2.9 × 104) towards 50 ppm NO2 gas at a comparatively low operating temperature (∼100 °C). The sensor response was found to increase linearly from 1.31 × 102 to 2.9 × 104 while the response time decrease from 12.4 to 1.6 min with increase in the concentration of NO2 gas from 1 to 50 ppm. The reaction kinetics of target NO2 gas on the surface of SnO2 thin film at the Sn sites play important role in enhancing the response characteristics at lower operating temperature (∼100 °C). The results obtained in the present study are encouraging for realization of SnO2 thin film based sensor for efficient detection of NO2 gas with low power consumption.
143 citations