Titanium-Doped P-Type WO3 Thin Films for Liquefied Petroleum Gas Detection

Gas sensors are an important part of smart homes in the era of the Internet of Things. In this work, we studied Ti-doped P-type WO3 thin films for liquefied petroleum gas (LPG) sensors. Ti-doped tungsten oxide films were deposited on glass substrates by direct current reactive magnetron sputtering from a W-Ti alloy target at room temperature. After annealing at 450 °C in N2 ambient for 60 min, p-type Ti-doped WO3 was achieved for the first time. The measurement of the room temperature Hall-effect shows that the film has a resistivity of 5.223 × 103 Ωcm, a hole concentration of 9.227 × 1012 cm−3, and mobility of 1.295 × 102 cm2V−1s−1. X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses reveal that the substitution of W6+ with Ti4+ resulted in p-type conductance. The scanning electron microscope (SEM) images show that the films consist of densely packed nanoparticles. The transmittance of the p-type films is between 72% and 84% in the visible spectra and the optical bandgap is 3.28 eV. The resistance increased when the films were exposed to the reducing gas of liquefied petroleum gas, further confirming the p-type conduction of the films. The p-type films have a quick response and recovery behavior to LPG.

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Morphological, optical and electrochromic properties of dry-lithiated nanostructured WO3 thin films

Materials Science-Poland ◽

10.2478/msp-2018-0048 ◽

2018 ◽

Vol 36 (2) ◽

pp. 341-347

Author(s):

K.V. Madhuri ◽

M. Bujji Babu

Keyword(s):

Thin Films ◽

Photoelectron Spectroscopy ◽

Optical Constants ◽

Near Infrared ◽

Lithium Content ◽

X Ray ◽

Glass Substrates ◽

Evaporation Technique ◽

Wo3 Thin Films ◽

Deposited Films

Abstract Tungsten trioxide (WO3) thin films were prepared by thermal evaporation technique on thoroughly cleaned glass substrates at high pressure of 133.322 mPa in presence of argon. The substrate temperature was maintained from 6 °C to 8 °C with the help of a cold jar. The deposited films were annealed at 400 °C in air for about 2 hours. The films were characterized in terms of their composition by X-ray photoelectron spectroscopy. Subsequently, the laboratory developed dry lithiation method was used to intercalate lithium atoms into as-deposited films in various proportions. With the amount of lithium content inserted into the film, the films showed coloration in visible and near infrared regions. The morphology, coloration efficiency and optical constants of annealed and lithiated films were calculated.

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Microstructural and Optical Properties of SnO Thin Film by Thermal Evaporation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.795.558 ◽

2013 ◽

Vol 795 ◽

pp. 558-562

Author(s):

Lee Siang Chuah ◽

Z. Mohamed ◽

Zainuriah Hassan

Keyword(s):

Thin Films ◽

Room Temperature ◽

Thermal Evaporation ◽

Hole Concentration ◽

Hexagonal Wurtzite Structure ◽

Thermal Evaporation Method ◽

Sem Image ◽

Glass Substrates ◽

Xrd Patterns ◽

P Type

In this work, we present results about the preparation and characterization of stannous oxide (SnO) thin films. SnO thin films were obtained via thermal evaporation method from SnO2powder as source material. These thin films were successfully deposited onto well cleaned glass substrates by thermal evaporation technique. The as deposited thin films were of thickness of 2500 Å and film were post-deposition annealed in air ambient at 400°C for 20 min and 40 min, respectively in a furnace. As-deposited films are highly conductive andptype. The best p-type SnO film annealed at 400 °C for 40 min shows a resistivity of 1.05 Ω·cm and a relatively high hole concentration of 2 × 1017cm3at room temperature. The X-ray diffraction (XRD) patterns of annealed films exhibit a polycrystalline hexagonal wurtzite structure without preferred orientation. The scanning electron microscopy (SEM) image shows the presence of uniformly dispersed spherical in shaped SnO particles. The mean grain sizes (diameter) are calculated to be about 80 and 100 nm for the p-type SnO films prepared at 400 °C for 20 min, and 40 min, respectively. Room temperature photoluminescence (PL) spectra of the SnO film exhibit two emission bands, around the wavelength of 300 nm and 450 nm. All spectra were measured at room temperature.

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P-Type Lithium Niobate Thin Films Fabricated by Nitrogen-Doping

Materials ◽

10.3390/ma12050819 ◽

2019 ◽

Vol 12 (5) ◽

pp. 819 ◽

Cited By ~ 5

Author(s):

Wencan Li ◽

Jiao Cui ◽

Weiwei Wang ◽

Dahuai Zheng ◽

Longfei Jia ◽

...

Keyword(s):

Thin Films ◽

Lithium Niobate ◽

Photoelectron Spectroscopy ◽

Hole Concentration ◽

Nitrogen Plasma ◽

Si Substrate ◽

Surface Appearance ◽

Type Conductivity ◽

X Ray ◽

P Type

Nitrogen-doped lithium niobate (LiNbO3:N) thin films were successfully fabricated on a Si-substrate using a nitrogen plasma beam supplied through a radio-frequency plasma apparatus as a dopant source via a pulsed laser deposition (PLD). The films were then characterized using X-Ray Diffraction (XRD) as polycrystalline with the predominant orientations of (012) and (104). The perfect surface appearance of the film was investigated by atomic force microscopy and Hall-effect measurements revealed a rare p-type conductivity in the LiNbO3:N thin film. The hole concentration was 7.31 × 1015 cm−3 with a field-effect mobility of 266 cm2V−1s−1. X-ray Photoelectron Spectroscopy (XPS) indicated that the atom content of nitrogen was 0.87%; N atoms were probably substituted for O sites, which contributed to the p-type conductivity. The realization of p-type LiNbO3:N thin films grown on the Si substrate lead to improvements in the manufacturing of novel optoelectronic devices.

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Reactive Dual Magnetron Sputtering: A Fast Method for Preparing Stoichiometric Microcrystalline ZnWO4 Thin Films

Surfaces ◽

10.3390/surfaces4020013 ◽

2021 ◽

Vol 4 (2) ◽

pp. 106-114

Author(s):

Yannick Hermans ◽

Faraz Mehmood ◽

Kerstin Lakus-Wollny ◽

Jan P. Hofmann ◽

Thomas Mayer ◽

...

Keyword(s):

Thin Films ◽

Magnetron Sputtering ◽

Photoelectron Spectroscopy ◽

Fast Method ◽

X Ray Diffraction ◽

X Ray ◽

Glass Substrates ◽

Post Annealing ◽

Rf Signal ◽

First Time

Thin films of ZnWO4, a promising photocatalytic and scintillator material, were deposited for the first time using a reactive dual magnetron sputtering procedure. A ZnO target was operated using an RF signal, and a W target was operated using a DC signal. The power on the ZnO target was changed so that it would match the sputtering rate of the W target operated at 25 W. The effects of the process parameters were characterized using optical spectroscopy, X-ray diffraction, and scanning electron microscopy, including energy dispersive X-ray spectroscopy as well as X-ray photoelectron spectroscopy. It was found that stoichiometric microcrystalline ZnWO4 thin films could be obtained, by operating the ZnO target during the sputtering procedure at a power of 55 W and by post-annealing the resulting thin films for at least 10 h at 600 °C. As FTO coated glass substrates were used, annealing led as well to the incorporation of Na, resulting in n+ doped ZnWO4 thin films.

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Comparative Study of ZnO Thin Films Grown on Quartz Glass and Sapphire (001) Substrates by Means of Magnetron Sputtering and High-Temperature Annealing

Applied Sciences ◽

10.3390/app9214509 ◽

2019 ◽

Vol 9 (21) ◽

pp. 4509

Author(s):

Weijia Yang ◽

Fengming Wang ◽

Zeyi Guan ◽

Pengyu He ◽

Zhihao Liu ◽

...

Keyword(s):

Thin Films ◽

High Temperature ◽

Magnetron Sputtering ◽

Comparative Study ◽

Quartz Glass ◽

Photoelectron Spectroscopy ◽

Zno Thin Films ◽

High Temperature Annealing ◽

X Ray ◽

Glass Substrates

In this work, we reported a comparative study of ZnO thin films grown on quartz glass and sapphire (001) substrates through magnetron sputtering and high-temperature annealing. Firstly, the ZnO thin films were deposited on the quartz glass and sapphire (001) substrates in the same conditions by magnetron sputtering. Afterwards, the sputtered ZnO thin films underwent an annealing process at 600 °C for 1 h in an air atmosphere to improve the quality of the films. X-ray diffraction, scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectra, photoluminescence spectra, and Raman spectra were used to investigate the structural, morphological, electrical, and optical properties of the both as-received ZnO thin films. The ZnO thin films grown on the quartz glass substrates possess a full width of half maximum value of 0.271° for the (002) plane, a surface root mean square value of 0.50 nm and O vacancies/defects of 4.40% in the total XPS O 1s peak. The comparative investigation reveals that the whole properties of the ZnO thin films grown on the quartz glass substrates are comparable to those grown on the sapphire (001) substrates. Consequently, ZnO thin films with high quality grown on the quartz glass substrates can be achieved by means of magnetron sputtering and high-temperature annealing at 600 °C.

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Synthesis and Characterization of Nb-Doped TiO2 Thin Films Prepared by RF Magnetron Sputtering

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1117.139 ◽

2015 ◽

Vol 1117 ◽

pp. 139-142 ◽

Cited By ~ 1

Author(s):

Marius Dobromir ◽

Radu Paul Apetrei ◽

A.V. Rogachev ◽

Dmitry L. Kovalenko ◽

Dumitru Luca

Keyword(s):

Thin Films ◽

Magnetron Sputtering ◽

Photoelectron Spectroscopy ◽

Rf Magnetron Sputtering ◽

X Ray ◽

Force Microscopy ◽

Glass Substrates ◽

Atomic Force ◽

Vis Spectroscopy ◽

Diffraction Patterns

Amorphous Nb-doped TiO2 thin films were deposited on (100) Si and glass substrates at room temperature by RF magnetron sputtering and a mosaic-type Nb2O5-TiO2 sputtering target. To adjust the amount of the niobium dopant in the film samples, appropriate numbers of Nb2O5 pellets were placed on the circular area of the magnetron target with intensive sputtering. By adjusting the discharge conditions and the number of niobium oxide pellets, films with dopant content varying between 0 and 16.2 at.% were prepared, as demonstrated by X-ray photoelectron spectroscopy data. The X-ray diffraction patterns of the as-deposited samples showed the lack of crystalline ordering in the samples. Surfaces roughness and energy band gap values increase with dopant concentration, as showed by atomic force microscopy and UV-Vis spectroscopy measurements.

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Structure and Electronic Properties of Evaporated Thin Films of Lead Sulfide

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.294.85 ◽

2009 ◽

Vol 294 ◽

pp. 85-92 ◽

Cited By ~ 1

Author(s):

A.A. Ibrahim

Keyword(s):

Thin Films ◽

Lead Sulfide ◽

Room Temperature ◽

Conduction Band Edge ◽

X Ray Diffraction ◽

X Ray ◽

Glass Substrates ◽

Temperature Electron ◽

Transition Voltage ◽

Dc Electrical Properties

Lead sulfide (PbS) thin films were prepared by thermal evaporation onto glass substrates from PbS powder. The structure and DC electrical properties of evaporated PbS thin film sandwich structures with thicknesses (d) up to 600 nm have been investigated. X-ray diffraction studies showed that the films were crystalline, with a preferred orientation in the [111] direction. Capacitance measurements indicated that the films had a relative permittivity of 5.7. Room-temperature current density-voltage (J–V) characteristics revealed ohmic conduction below a transition voltage (Vt) and a power–law dependence with an exponent of ≈ 2 at higher voltages. This behaviour was interpreted in terms of space–charge limited conductivity controlled by an exponential distribution of traps below the conduction band edge. Further evidence for this conduction process was provided by a linear dependence of Vt upon d2. Analysis of the results yielded a room temperature electron concentration no of ≈ (3.9 – 5.4) x 109 m-3.

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Effects of Substrate Temperature on the Properties of Silicon Oxide Films by PECVD

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.198-199.28 ◽

2012 ◽

Vol 198-199 ◽

pp. 28-31

Author(s):

Chun Ya Li ◽

Xi Feng Li ◽

Long Long Chen ◽

Ji Feng Shi ◽

Jian Hua Zhang

Keyword(s):

Thin Film ◽

Thin Films ◽

Electrical Properties ◽

Photoelectron Spectroscopy ◽

Deposition Temperature ◽

Silicon Oxide ◽

Chemical Vapor ◽

Growth Conditions ◽

X Ray ◽

Glass Substrates

Under different growth conditions, silicon Oxide (SiOx) thin films were deposited successfully on Si (100) substrates and glass substrates by plasma enhanced chemical vapor deposition (PECVD). The thickness, refractive index and growth rate of the thin films were tested by ellipsometer. The effects of deposition temperature on the structure and properties of SiOx films were studied using X ray diffraction (XRD), X ray photoelectron spectroscopy (XPS) and UV-Visible spectroscopy. The results show that the SiOx films were amorphous at different deposition temperature. The peaks of Si2p and O1s shifted to higher binding energy with temperature increasing. The SiOx films had high transmissivity at the range of 400-900nm. By analyzing the observation and data, the influence of deposition parameters on the electrical properties and interface characteristics of SiOx thin film prepared by PECVD is systematically discussed. At last, SiOx thin film with excellent electrical properties and good interface characteristic is prepared under the relatively optimum parameters.

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XRD and XPS studies of room temperature spontaneous interfacial reaction of CeO2 thin films on Si and Si3N4 substrates

RSC Advances ◽

10.1039/c4ra09882j ◽

2014 ◽

Vol 4 (108) ◽

pp. 62935-62939 ◽

Cited By ~ 29

Author(s):

Parthasarathi Bera ◽

Chinnasamy Anandan

Keyword(s):

Thin Films ◽

Interfacial Reaction ◽

Photoelectron Spectroscopy ◽

Room Temperature ◽

Interfacial Reactions ◽

X Ray Diffraction ◽

X Ray

X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) investigations of interfacial reactions between Ce and Si have been carried out on as-deposited and 15 month aged CeO2/Si and CeO2/Si3N4 thin films.

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Electrodeposition and Properties of CuInS2 Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.1659 ◽

2013 ◽

Vol 690-693 ◽

pp. 1659-1663

Author(s):

Hai Fang Zhou ◽

Xiao Hu Chen

Keyword(s):

Thin Films ◽

Photocurrent Density ◽

Enhancement Effect ◽

X Ray Diffraction ◽

X Ray ◽

Glass Substrates ◽

Ito Glass ◽

Type Semiconductor ◽

One Step ◽

P Type

The preparation and characterization of CuInS2 thin films on ITO glass substrates prepared by one-step electrodeposition have been reported. Samples were characterized using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). The results indicate that CuInS2 is the major phase for the film deposited at -1.0 V, after annealing at 550°C in sulfur atmosphere, and the sample is Cu-rich and p-type semiconductor. Additionally, the energy band gap and carrier concentration for the sample were found to be 1.43 eV and 4.20×1017 cm−3, respectively. Furthermore, the maximum photocurrent density of the sample was found to be -1.15 mA/cm2 under 255 lx illumination, the sample shows the photo-enhancement effect.

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