- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Highly sensitive and selective room-temperature NO2 gas-sensing characteristics of SnOX-based p-type thin-film transistor
摘要： The high-performance p-type metal-oxide-semiconductor (MOS)-based gas sensor is an important subject of research in the field of gas-sensing technology. In this work, we demonstrated a p-type MOS-based thin-film transistor (TFT) nitrogen dioxide (NO2) gas sensor that used tin oxide (SnOX) for both the channel and sensing layers. The crystalline status, surface morphology, and atomic-bonding configuration of the thin-film were examined using X-ray diffraction, field emission-scanning electron microscopy, and X-ray photoelectron spectroscopy. The results indicated that the deposited thin-film was mainly composed of polycrystalline SnO with a tetragonal structure. The fabricated p-type SnOX TFT showed a maximum response value of 19.4-10 ppm NO2 at room temperature (RT, 25 °C) when operated in the subthreshold region, which was significantly higher than that of 2.8–10 ppm NO2 obtained from a p-type SnOX thin-film chemiresistor at RT. In addition, the SnOX TFT gas sensor showed significantly higher sensitivity to NO2 gas than to other target gases such as NH3, H2S, CO2, and CO at RT. To the best of our knowledge, this is the first study to a p-type MOS-based field-effect transistor-type gas sensor. Our experimental results demonstrate that the p-type SnOX TFT is a promising gas sensor that can operate at RT with high sensitivity and selectivity to NO2 gas.
关键词： SnO,Thin-film transistor,NO2 gas sensing,SnOX,P-type metal oxide semiconductor
更新于2025-11-21 11:01:37
-
General Synthesis of Ordered Mesoporous Rare-Earth Orthovanadate Thin Films and Their Use as Photocatalysts and Phosphors for Lighting Applications
摘要： Herein, the block copolymer templating sol-gel synthesis of a novel class of ternary oxide nanomaterials is reported. NdVO4, EuVO4, GdVO4, DyVO4, YVO4, and TmVO4 have been prepared as open mesoporous films by the dip-coating method using hydrated rare-earth nitrate salt precursors along with vanadium oxytrichloride. All materials crystallize in the tetragonal ZrSiO4-type structure with space-group I41/amd. Short-term treatment at 550 °C is found sufficient to initiate crystallization. Characterization via X-ray and electron diffraction, Raman and X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry confirms the single-phase nature and uniformity of the different orthovanadates with tailorable crystallite sizes. The integrated results from electron and atomic force microscopy, Kr-physisorption as well as in-situ and ex-situ synchrotron-based small-angle X-ray scattering reveal that the porosity persists throughout the thickness of films and the mesoscopic ordering is retained even after heating in air at 700 °C. Photobleaching experiments indicate that the sol-gel derived materials, showing an indirect band gap transition at (3.8±0.1) eV, exhibit good photocatalytic properties—the activity is highly superior to that of bulk films of the same nominal composition. Moreover, when doping GdVO4, YVO4, and solid solution GdVO4-YVO4 with trivalent rare-earth ions such as Eu3+, Dy3+, Er3+, or Tm3+ ions, the films hold promise as phosphors for lighting applications, which might pave the way toward development of (3-dimensional) intricate nanocomposites with unprecedented functionalities.
关键词： Block copolymer templating,ternary metal oxide nanostructure,photocatalyst,phosphor,sol-gel chemistry
更新于2025-11-21 10:59:37
-
Photocatalytic and Antimicrobial Properties of Ga Doped and Ag Doped ZnO Nanorods for Water Treatment
摘要： Water contamination is a worldwide concerning problem. Emerging contaminants have made conventional water treatment processes ineffective. This makes the search for new materials with improved physical-chemical properties for water treatment an urgent necessity. Doping metal oxides nanostructures can improve the photocatalytic degradation of contaminants and the antimicrobial activity of the material. During this process, water treatment not only involves the degradation of toxic pollutants, but also the elimination of virus and bacteria. Then, it is important to study not only the effect of a dopant in a material as photocatalyst but also the effect in its antimicrobial properties. In this work ZnO nanorods, Ga doped ZnO nanorods and Ag doped ZnO nanorods are synthesized and supported in polyethylene by a fast-hydrothermal microwave heating synthesis. Their photocatalytic performance and antimicrobial properties for water treatment were evaluated. Experiments show that Ag and Ga can improve the photocatalytic and antimicrobial properties of ZnO nanorods; the relationship between doping concentrations, with both the toxicity effect of the nanorods toward bacteria and the nanorods photocatalytic performance, is shown.
关键词： doping,water,antimicrobial,nanorods,contamination,metal oxide,photocatalysis,zinc oxide
更新于2025-11-19 16:56:35
-
Influence of pretreatment on surface interaction between Cu and anatase-TiO2 in the simultaneous photoremediation of nitrate and oxalic acid
摘要： Copper-promoted anatase-type TiO2 photocatalysts (2.5 wt% Cu) were prepared by wet impregnation onto TiO2 which was pre-calcined at 600°C and the other not subjected to any thermal pre-treatment. In the latter case, the material was inactive for the photo-reduction of nitrate whereas 600°C pre-calcined TiO2 yielded a material which was active for the same reaction. The surface properties of the materials were determined by BET Surface area, SEM TEM, XRD, XPS, TPR, UV-Visible diffuse reflectance, DTA, N2O pulsed chemisorption and FTIR studies. The BET and XRD and DTA showed that pre-calcination of TiO2 stabilised the support, but coalescence of particles was observed in TiO2 that was not subjected to any thermal pre-treatment as evidenced by crystallite growth. Similarly, XPS, FTIR and TPR proved the formation of Cu2O particles on the surface of pre-calcined TiO2. On the other hand, the absence of pre-calcination step resulted in interring of Cu species within the grown anatase crystallites that hindered their proper distribution over TiO2, helped in its inactiveness in the photoreduction of nitrate. However, the prepared material using pre-calcined TiO2 showed the overall nitrate and oxalic acid removal efficiency of 31 and 70% with N2 and NH4+ selectivity of 44.9 and 55.1 %, respectively. The results provide insight into the significance of activity-structure relation, inferring that the two surfaces were chemically not similar. Thus, as even supported by adsorption experiment, difference in photocatalytic behaviour amongst the prepared materials was a function of crystallinity, particle size, absence of surface defect and high energy sites.
关键词： Nitrate,photocatalyst,photoremediation,metal oxide-support interaction,oxalic acid
更新于2025-11-19 16:56:35
-
Determination of physical mechanism responsible for the capacitance-voltage weak inversion “hump” phenomenon in n-InGaAs based metal-oxide-semiconductor gate stacks
摘要： Weak inversion capacitance-voltage (C-V) “hump” is a widely observed phenomenon at n-InGaAs based metal oxide semiconductor (MOS) structures. The mechanism responsible for this phenomenon is still under discussion. The C-V hump can be explained as an interaction of interface states with either one or both semiconductor energy bands. Each of the proposed mechanisms leads to a different interpretation of C-V hump. Simulating the mechanisms by relevant equivalent circuits, the capacitance and conductance characteristics of the MOS structure were calculated and compared with experimental results. The mechanism responsible for the C-V hump was determined.
关键词： interface states,equivalent circuits,n-InGaAs,metal-oxide-semiconductor,capacitance-voltage hump
更新于2025-11-14 17:28:48
-
Laser-induced synthesis and photocatalytic properties of hybrid organic–inorganic composite layers
摘要： A laser-based method was developed for the synthesis and simultaneous deposition of multicomponent hybrid thin layers consisting of nanoentities, graphene oxide (GO) platelets, transition metal oxide nanoparticles, urea, and graphitic carbon nitride (g-C3N4) for environmental applications. The photocatalytic properties of the layers were tested through the degradation of methyl orange organic dye probing molecule. It was further demonstrated that the synthesized hybrid compounds are suitable for the photodegradation of chloramphenicol, a widely used broad-spectrum antibiotic, active against Gram-positive and Gram-negative bacteria. However, released in aquatic media represents a serious environmental hazard, especially owing to the formation of antibiotic-resistant bacteria. The obtained results revealed that organic, urea molecules can become an alternative to noble metals co-catalysts, promoting the separation and transfer of photoinduced charge carriers in catalytic composite systems. Laser radiation induces the reduction of GO platelets and the formation of graphene-like material. During the same synthesis process, g-C3N4 was produced, by laser pyrolysis of urea molecules, without any additional heat treatment. The layers exhibit high photocatalytic activity, being a promising material for photodegradation of organic pollutants in wastewater.
关键词： transition metal oxide nanoparticles,urea,photocatalytic properties,hybrid organic–inorganic composite layers,graphene oxide,graphitic carbon nitride,methyl orange,laser-based synthesis,chloramphenicol
更新于2025-11-14 17:04:02
-
High-Mobility Inkjet-Printed Indium-Gallium-Zinc-Oxide Thin-Film Transistors Using Sr-Doped Al2O3 Gate Dielectric
摘要： In this paper, we demonstrate high-mobility inkjet-printed indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs) using a solution-processed Sr-doped Al2O3 (SAO) gate dielectric. Particularly, to enhance to the electrical properties of inkjet-printed IGZO TFTs, a linear-type printing pattern was adopted for printing the IGZO channel layer. Compared to dot array printing patterns (4 × 4 and 5 × 5 dot arrays), the linear-type pattern resulted in the formation of a relatively thin and uniform IGZO channel layer. Also, to improve the subthreshold characteristics and low-voltage operation of the device, a high-k and thin (~10 nm) SAO film was used as the gate dielectric layer. Compared to the devices with SiO2 gate dielectric, the inkjet-printed IGZO TFTs with SAO gate dielectric exhibited substantially high field-effect mobility (30.7 cm2/Vs). Moreover, the subthreshold slope and total trap density of states were also significantly reduced to 0.14 V/decade and 8.4 × 1011/cm2·eV, respectively.
关键词： metal-oxide semiconductors,thin-film transistors,high-k dielectric,high mobility,inkjet printing
更新于2025-11-14 15:19:41
-
A Comparative Study of Gas Sensing Properties of Tungsten Oxide, Tin Oxide and Tin-Doped Tungsten Oxide Thin Films for Acetone Gas Detection
摘要： Nowadays, various metal oxide thin films have been used for the purpose of gas sensing. This research depicts a comparison of gas sensing properties among four different metal oxide thin films, namely, tungsten dioxide (WO2), tungsten trioxide (WO3), tin oxide (SnO2) and tin doped tungsten trioxide (Sn-doped WO3), for detecting acetone gas. Each metal oxide thin film was subjected to acetone gas flow of various concentrations and the corresponding changes in resistance were calculated. Characterizations such as x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and gas sensing characterization for recording resistance changes have been performed. Each film was annealed at different temperatures for 1 h (WO2 and WO3 at 500°C, SnO2 at 300°C and Sn-doped WO3 at 400°C) so as to achieve an optimum grain size for sensing. The XRD patterns reveal formation of an orthorhombic phase of WO2, hexagonal phase of WO3 and orthorhombic phase of SnO2. AFM and SEM depict clear images of grain boundaries on the film. SnO2 has been found to be the best thin film for sensing acetone gas. Operational optimum temperature for sensing acetone gas has been calculated for each thin film (260°C for WO2, 220°C for WO3, 360°C for SnO2 and 300°C for Sn-doped WO3). It can detect a very low concentration of 1.5 ppm acetone gas with a good resistance response change of 30%. Various concentrations of acetone gas, namely, 1.5 ppm, 3 ppm, 5 ppm, 7 ppm, 10 ppm, 15 ppm and 20 ppm, have been detected using these metal oxide thin films, and thus the comparison has been made. The response time for SnO2 is approximately 3 min and recovery time is approximately 4 min.
关键词： tungsten oxide,acetone gas detection,topography,tin oxide,Metal oxide thin films,surface metrology,gas sensing,tin-doped tungsten oxide
更新于2025-09-23 15:23:52
-
Effect of O <sub/>2</sub> Flow Rate on Properties of Mn–SnO <sub/>2</sub> /Ag/Mn–SnO <sub/>2</sub> Multilayer Film
摘要： Multilayer films with Mn–SnO2 (MTO)/Ag/Mn–SnO2 (MTO) hybrid structure were prepared on a flexible polyethylene terephthalate (PET) substrate using a DC/RF sputtering system at room temperature. The optical, electrical, and structural properties of the thus-synthesized multilayer films were systematically investigated as a function of the O2/(Ar + O2) flow rate. The transmittance of the MTO/Ag/MTO multilayer films at 550 nm increased gradually from 83.1% to 87.9% and the sheet resistance (Rs) of the multilayer films increased from 6.3 to 9.8 Ω/sq upon increasing the O2/(Ar + O2) flow rate. The highest figure of merit (ΦTC) of the MTO/Ag/MTO multilayer film was 45.7 × 10?3 Ω?1 at an O2/(Ar + O2) flow rate of 2.8%. X-ray photoelectron spectra of multilayer films obtained with different O2/(Ar + O2) flow rates showed no noticeable variation.
关键词： Sheet Resistance,Figure of Merit,Transmittance,Gas Mixture Rate,Oxide/Metal/Oxide Structure
更新于2025-09-23 15:23:52
-
The study of Fe-doped CdS nanoparticle-assisted photocatalytic degradation of organic dye in wastewater
摘要： Size-tunable nanoparticles (NPs) for pristine cadmium sulfide (CdS) and iron (Fe)-doped (5, 10 and 15%) CdS were synthesized using facile chemical co-precipitation. Size-controlled NPs were prepared with thioglycolic acid (TGA) as the capping agent and their structural, optical, morphological and physiochemical evaluations were performed using X-ray diffraction (XRD), UV–visible spectroscopy, Raman spectroscopy, field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FTIR). XRD revealed single cubic phase of CdS and later broader peaks upon mixing of Fe, and intensive absorption was recorded in the visible regime upon doping with redshift. FESEM confirmed spherical nanoparticles of Fe–CdS, and Cd–S linkage along with other functional groups was recognized by FTIR. Cd1?xFexS (x = 0, 0.05, 0.10 and 0.15) powder was used as the photocatalyst for methylene blue (MB) degradation in visible light and catalyst in NaBH4’s presence. The control CdS bleached MB faster than doped but doped CdS showed higher catalytic degradation. The Fe-doped CdS NPs showed superior catalytic potential compared to undoped CdS which suggests their use in dye industries, especially leather and tanneries. Additionally, NPs not only show superior catalytic characteristics but also help in cost reduction and complete removal of dyes for wastewater management.
关键词： Metal oxide,Photocatalytic activity,XRD,Graphene,Sol–gel
更新于2025-09-23 15:23:52