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1.
Combining the spray pyrolysis and the sol–gel techniques gives the possibility to produce Fluorine doped Tin oxide (SnO2:F) thin films. Transparent conducting SnO2:F thin films have been deposited on glass substrates by the spray pyrolysis technique. This technique for the fabrication of SnO2:F filmsby combining sol–gel process and the spray pyrolysis technique ispresented in this paper. The Sol–gel precursors have been successfully prepared using SnCl2·5H2O and (Ac)F3. The structural, electrical, and optical properties of these films were investigated. The high resolution transmission electron microscopy (HRTEM) and selected area diffraction (SAD) patterns of SnO2:F films show that the gel films lead to a tetragonal structure. The X‐ray diffraction pattern of the films deposited at substrate temperature 530° , the orientation of the films was predominantly [110]. In addition, the surface chemical components were also examined by X‐ray photoelectron spectroscopy (XPS) showing the SnO2:F deposited with the atomic concentration ratios Sn/F 1.82:1. The minimum sheet resistance was 50 Ω and average transmission in the visible wavelength range of 300 to 800 nm was 87.25%. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

2.
A series of tin‐doped hydroxypropyl cellulose (HPC) lyotropic liquid crystal (LC) was synthesized using a simple process and their properties were characterized using selective reflection, wide‐angle X‐ray diffraction (WAXD), and the band texture observed under polarized optical microscope. The present preparation is applicable for mass production using large substrate with low cost HPC. A cholesteric lyotropic LC phase was observed for the hybrid solution with higher than 40 wt % HPC. After sol–gel condensation, the HPC‐Sn hybrid LC films were calcined at 400 °C and the as‐prepared product was determined to obtain tin dioxide (SnO2) which was characterized using WAXD. The iridescent color and ~2 nm structure seen after the condensation disappeared in the as‐prepared SnO2. Scanning electronic microscope images of the SnO2 showed that the HPC content in the HPC‐Sn hybrid played an important role in controlling the SnO2 morphology. A spectrum of relatively monochromatic extreme ultraviolet (13.5 nm) emission was measured in the as‐prepared SnO2 in comparison with bulk tin and inverse opal SnO2. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4566–4576, 2009  相似文献   

3.
Tin oxide (SnOx) has been widely used for the fabrication of transparent and flexible devices because of its excellent optical and electronic properties. In this work, we established a methodology for the synthesis of SnOx thin films with p‐type and n‐type tunable conductivity by direct currecnt (DC) magnetron sputtering. The SnOx thin films changed from p‐type to n‐type by increasing the relative oxygen partial pressure (ppO2) from 4.8% to 18.5% and by varying the working pressure between 1.8 and 2.5 mTorr. The SnOx thin films were annealed at 160°C, 180°C, and 200°C for 30 min to promote the formation of the desired crystalline structures. At the annealing temperature of 180°C in air ambient, the SnOx thin films showed a tetragonal structure with Sn traces. Having found the optimal conditions, we deposited both types of SnOx thin films with the same tetragonal structure and similar chemical stoichiometry. Also, the conditions to obtain thin films with the highest mobility values for p‐type (1.10 cm2/Vs) and n‐type (22.20 cm2/Vs) were used for fabricating the device. Finally, the implementation of a SnOx‐based p–n diode was demonstrated using transparent SnOx thin films developed in this work, illustrating their potential use in transparent electronics.  相似文献   

4.
A new single‐source precursor, [SnCl4{OC(H)OC2H5}2], prepared by treating tin tetrachloride with ethyl formate (1:2 ratio) was developed for the deposition of tin oxide thin films on glass substrates. The compound [SnCl4{OC(H)OC2H5}2] is highly volatile and provides very high growth rates (up to 100Å s?1 at 560 °C) in an atmospheric pressure chemical vapor deposition (APCVD) reactor. More significantly, the compound does not decompose to tin oxide below 320 °C, thereby minimizing the formation of particles in the vapor above the growing tin oxide film. To prepare highly conducting fluorine doped tin oxide (SnO2:F) films 2,2,2‐trifluoroethyl trifluoroacetate was used as the source of fluoride. High quality SnO2:F films were deposited at 560 °C with a flow rate of 2 mL fluoride reagent hr?1; typical film properties are resistivity of 5.9 X 10?4 Ω cm, Hall mobility of 27.3 cm2 V?1 s?1, carrier concentration of 3.9 X 1020 cm?3 and percent transmission ranging from 86 to 88 %. The best films of SnO2:F possess transparencies as high as 90 % (750 nm), sheet resistances as low as 7 Ω sq?1 and Haacke's figure of merit as high as 29 X 10?3 (750 nm). The newly developed APCVD reactor and the chemistry were optimized with respect to structural, electrical and optical properties of the films by adjusting the substrate temperature, gas flow rates and the amount of fluoride present in the vapor stream. Growth rates with respect to deposition time, substrate temperature and flow rates of precursors were found to be similar for both undoped (SnO2) and doped (SnO2:F) samples. The SnO2:F films possess larger grains than the SnO2 which may account for the lower resistivity and the higher mobility in the SnO2:F samples.  相似文献   

5.
In this work, tin(II) oxalate was studied as a novel chloride-free starting material for the preparation of a stable Sn-containing precursor solution. This precursor was applied for the chemical solution deposition (CSD) of transparent conducting coatings of SnO2 on Si/SiO2 substrates. An influence of synthesis parameters, such as pH, complexing agent to metal ion ratio on the stability of the citrato peroxo Sn(IV) precursor has been investigated in this study. Insights into the precursor chemistry and its thermal decomposition based on TG-DSC analysis are also presented. The obtained SnO2 films were characterized by high temperature X-ray diffraction (HT-XRD) and scanning electron microscopy (SEM) to evaluate phase purity and film thickness, respectively.  相似文献   

6.
Nine organotin fluorocarboxylates RnSnO2CRf (n = 3, R = Bu, Rf = CF3, C2F5, C3F7, C7F15; R = Et, Rf = CF3, C2F5; R = Me, Rf = C2F5; n = 2, R = Me, Rf = CF3) have been synthesized; key examples have been used to deposit fluorine‐doped SnO2 thin films by atmospheric pressure chemical vapour deposition. Et3SnO2CC2F5, in particular, gives high‐quality films with fast deposition rates despite adopting a polymeric, carboxylate‐bridged structure in the solid state, as determined by X‐ray crystallography. Gas‐phase electron diffraction on the model compound Me3SnO2CC2F5 shows that accessible conformations do not allow contact between tin and fluorine, and that direct transfer is therefore unlikely to be part of the mechanism for fluorine incorporation in SnO2 films. The structure of Me2Sn(O2CCF3)2(H2O) has also been determined and adopts a trans‐Me2SnO3 coordination sphere about tin in which each carboxylate group is monodentate. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

7.
SnO2-based materials are used as sensors, catalysts and in electro–optical devices. This work aims to synthesize and characterize the SnO2/Sb2O3-based inorganic pigments, obtained by the polymeric precursor method, also known as Pechini method (based on the metallic citrate polymerization by means of ethylene glycol). The precursors were characterized by thermogravimetry (TG) and differential thermal analysis (DTA). After characterization, the precursors were heat-treated at different temperatures and characterized by X-ray diffraction. According to the TG/DTA curves basically two-step mass loss process was observed: the first one is related to the dehydration of the system; and the second one is representative to the combustion of the organic matter. Increase of the heat treatment temperature from 500 to 600°C and 700°C resulted higher crystallinity of the formed product.  相似文献   

8.
The effects of UV irradiation on the properties of Sb5+ doped gel films were studied, which were prepared from stannic chloride (SnCl4·5H2O) and sodium alkoxide (NaOR) modified with benzytone (BzAcH). It was found that the absorption peak at around 335 nm due to the π → π* transition showed the formation of a chelate ring to Sn. The intensity of the absorption band decreased with UV light irradiation at 365 nm from a high‐pressure mercury lamp (250W). This finding showed that the SnO2:Sb gel films modified with BzAcH were photosensitive to UV light. Additionally, this finding was applied to the fabrication of patterns on the SnO2:Sb thin films. A gel film was irradiated through a mask and leached in water. Then a positive pattern was formed on the SnO2:Sb thin films attached to the substrate. After heat treatment, the SnO2:Sb gel films changed into transparent conductive films with an average conductivity of 1.20 × 10?2Ω cm and with a transmission of 97.1%. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

9.
Well‐controlled nanostructures and a high fraction of Sn/Li2O interface are critical to enhance the coulombic efficiency and cyclic performance of SnO2‐based electrodes for lithium‐ion batteries (LIBs). Polydopamine (PDA)‐coated SnO2 nanocrystals, composed of hundreds of PDA‐coated “corn‐like” SnO2 nanoparticles (diameter ca. 5 nm) decorated along a “cob”, addressed the irreversibility issue of SnO2‐based electrodes. The PDA‐coated SnO2 were crafted by capitalizing on rationally designed bottlebrush‐like hydroxypropyl cellulose‐graft‐poly (acrylic acid) (HPC‐g ‐PAA) as a template and was coated with PDA to construct a passivating solid‐electrolyte interphase (SEI) layer. In combination, the corn‐like nanostructure and the protective PDA coating contributed to a PDA‐coated SnO2 electrode with excellent rate capability, superior long‐term stability over 300 cycles, and high Sn→SnO2 reversibility.  相似文献   

10.
The title compound, [Sn2(C9H12N)4O(OH)2], consists of two [2‐(Me2NCH2)C6H4]2SnOH units bridged by an O atom located on a twofold rotation axis. The unique Sn atom is six‐coordinated with a (C,N)2SnO2 octahedral core, as a result of the strong intramolecular N→Sn dative coordination trans to the Sn—O bonds [N—Sn—O = 170.24 (12) and 167.83 (10)°]. Owing to the presence of intermolecular H...phenyl contacts, the molecules are arranged in a ladder‐like structure.  相似文献   

11.
The complexes Me2SnL2 ( I ), Me3SnL ( II ), Et2SnL2 ( III ), n‐Bu2SnL2 ( IV ), n‐Bu3SnL ( V ), n‐Oct2SnL2 ( VI ), Bz2SnL2 ( VII ), and Ph3SnL ( VIII ), where “L” is ( E )‐3‐(3‐fluorophenyl)‐2‐phenyl‐2‐propenoate, have been prepared and structurally characterized by means of elemental analysis, infrared, mass, and multinuclear (1H, 13C, 119Sn) NMR spectral techniques. The spectroscopic results showed that the geometry around the Sn atom in triorganotin(IV) derivatives is four‐coordinated in noncoordinating solvent and behaves as five‐coordinated linear polymers with bridging carboxylate groups or five‐coordinated monomers, both acquiring trans‐R3SnO2 geometry for Sn in the solid state. While all the diorganotin(IV) derivatives may acquire trigonal bipyramidal structures in solution due to collapse of the Sn←OCO interaction and octahedral geometries in the solid state, which have been confirmed by the X‐ray crystallographic data of the compound III . The crystal structure of Et2SnL2 ( III ) has been determined by X‐ray crystallography and is found skew‐trapezoidal bipyramidal, which substantiates that the ligand acts as an anisobidentate chelating agent, thus rendering the Sn atom six coordinated. The crystal is monoclinic with space group C21/n. All the investigated compounds have also been screened for biocidal and cytotoxicity data. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:420–432, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20243  相似文献   

12.
Micrometer‐sized hierarchical Sn3O2(OH)2 octahedra, which are self‐assembled one inside the other, resembling “Russian doll” organization, have been obtained by a metalorganic approach. This synthesis is based on the controlled hydrolysis of [Sn(NMe2)2]2 in the presence of an alkylamine ligand in an organic solvent (THF). The water content of the medium proved to be a key parameter for the formation of these multi‐walled octahedra. The resultant structures have been used as gas‐sensitive layers on micromachined silicon devices. During in situ heating, Sn3O2(OH)2 is oxidized to SnO2 while retaining the initial morphology. The sensors present outstanding dynamic responses at very low CO concentrations (7 % and 67 % resistance variation to 0.25 and 20 ppm CO, respectively, at an operating temperature of 500 °C). This superior gas‐sensing performance is closely related to the unique microstructure of the SnO2 multi‐walled octahedra.  相似文献   

13.
Perfluoroalkytin compounds R(4−n)Sn(Rf)n (R = Me, Et, Bu, Rf = C4F9, n = 1; R = Bu, Rf = C4F9, n = 2, 3; R = Bu, Rf = C6F13, n = 1) have been synthesized, characterized by 1H, 13C, 19F and 119Sn NMR, and evaluated as precursors for the atmospheric pressure chemical vapour deposition of fluorine‐doped SnO2 thin films. All precursors were sufficiently volatile in the range 84–136 °C and glass substrate temperatures of ca 550 °C to yield high‐quality films with ca 0.79–2.02% fluorine incorporation, save for Bu3SnC6F13, which incorporated <0.05% fluorine. Films were characterized by X‐ray diffraction, scanning electron microscopy, thickness, haze, emissivity, and sheet resistance. The fastest growth rates and highest quality films were obtained from Et3SnC4F9. An electron diffraction study of Me3SnC4F9 revealed four conformations, of which only the two of lowest abundance showed close F Sn contacts that could plausibly be associated with halogen transfer to tin, and in each case it was fluorine attached to either the γ‐ or δ‐carbon atoms of the Rf chain. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

14.
Reactions of di‐n‐butyltin(IV) oxide with 4′/2′‐nitrobiphenyl‐2‐carboxylic acids in 1 : 1 and 1 : 2 stoichiometry yield complexes [{(n‐C4H9)2Sn(OCOC12H8NO2?4′/2′)}2O]2 ( 1 and 2 ) and (n‐C4H9)2Sn(OCOC12H8NO2?4′/2′)2 ( 3 and 4 ) respectively. These compounds were characterized by elemental analysis, IR and NMR (1H, 13C and 119Sn) spectroscopy. The IR spectra of these compounds indicate the presence of anisobidentate carboxylate groups and non‐linear C? Sn? C bonds. From the chemical shifts δ (119Sn) and the coupling constants 1J(13C, 119Sn), the coordination number of the tin atom and the geometry of its coordination sphere have been suggested. [{(n‐C4H9)2Sn(OCOC12H8NO2?4′)}2O]2 ( 1 ) exhibits a dimeric structure containing distannoxane units with two types of tin atom with essentially identical geometry. To a first approximation, the tin atoms appear to be pentacoordinated with distorted trigonal bipyramidal geometry. However, each type of tin atom is further subjected to a sixth weaker interaction and may be described as having a capped trigonal bipyramidal structure. The diffraction study of the complex (n‐C4H9)2Sn(OCOC12H8NO2?4′)2 ( 3 ) shows a six–coordinate tin in a distorted octahedral frame containing bidentate asymmetric chelating carboxylate groups, with the n‐Bu groups trans to each other. The n‐Bu? Sn? n‐Bu angle is 152.8° and the Sn? O distances are 2.108(4) and 2.493(5) Å. The oxygen atom of the nitro group of the ligand does not participate in bonding to the tin atom in 1 and 3 . Crystals of 1 are triclinic with space group P1 and of that of 3 have orthorhombic space group Pnna. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

15.
Reaction of dichloro‐ and dibromodimethyltin(IV) with 2‐(pyrazol‐1‐ylmethyl)pyridine (PMP) afforded [SnMe2Cl2(PMP)] and [SnMe2Br2(PMP)] respectively. The new complexes were characterized by elemental analysis and mass spectrometry and by IR, Raman and NMR (1H, 13C) spectroscopies. Structural studies by X‐ray diffraction techniques show that the compounds consist of discrete units with the tin atom octahedrally coordinated to the carbon atoms of the two methyl groups in a trans disposition (Sn? C = 2.097(5), 2.120(5) Å and 2.110(6), 2.121(6) Å in the chloro and in the bromo compounds respectively), two cis halogen atoms (Sn? Cl = 2.4908(16), 2.5447(17) Å; Sn? Br = 2.6875(11), 2.7464(9) Å) and the two donor atoms of the ligand (Sn? N = 2.407(4), 2.471(4) Å and 2.360(5), 2.455(5) Å). In both cases, the Sn? N(pyridine) bond length is markedly longer than the Sn? N(pyrazole) distance. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

16.
Electrochemical conversion of CO2 into energy‐dense liquids, such as formic acid, is desirable as a hydrogen carrier and a chemical feedstock. SnOx is one of the few catalysts that reduce CO2 into formic acid with high selectivity but at high overpotential and low current density. We show that an electrochemically reduced SnO2 porous nanowire catalyst (Sn‐pNWs) with a high density of grain boundaries (GBs) exhibits an energy conversion efficiency of CO2‐into‐HCOOH higher than analogous catalysts. HCOOH formation begins at lower overpotential (350 mV) and reaches a steady Faradaic efficiency of ca. 80 % at only −0.8 V vs. RHE. A comparison with commercial SnO2 nanoparticles confirms that the improved CO2 reduction performance of Sn‐pNWs is due to the density of GBs within the porous structure, which introduce new catalytically active sites. Produced with a scalable plasma synthesis technology, the catalysts have potential for application in the CO2 conversion industry.  相似文献   

17.
A laser-assisted chemical vapor deposition scheme for SnO2 films has been developed, based on the UV multiphoton dissociation of di (n-butyl) tin diacetate. Doped films were produced by simultaneous photolysis of other inorganic precursors. Films were characterized by UV–visible spectroscopy, room-temperature resistance measurements in the presence of a variety of gas-phase contaminants, and the temperature dependence of film resistance. These preliminary investigations demonstrate the ability to vary detection sensitivity and selectivity by changing the dopant precursor identity. © 1997 by John Wiley & Sons, Ltd.  相似文献   

18.
The 119Sn cross polarization‐magic angle spinning NMR spectrum of bis[1,3‐bis(3‐oxapentamethylenecarbamoylthioacetato)‐1,1,3,3‐tetrabutyl‐1,3‐distannoxane], {[(C4H9)2SnO2CCH2SC(O)N(CH2CH2)2O]2O}2, which consists of two resonances of similar chemical shifts and symmetry (δiso = −152, −202 ppm; asymmetry, κ = 0.38), implies the existence of two five‐coordinate tin sites in the centrosymmetric dimer. The assignment has been corroborated by X‐ray diffraction analysis on the compound that has been crystallized from ethanol; the crystal structure shows two tin atoms in cis‐C2SnO3 trigonal‐bipyramidal coordination [C‐Sn‐C = 131.5(1), 131.3(2) °]. The analysis also reveals the presence of two lattice ethanol molecules that are hydrogen‐bonded to the dimer [OO = 2.779(5) Å]. When exposed to air, the distannoxane loses ethanol. The unsolvated distannoxane is more active than cis‐platin when screened against MCF‐7 (mammary cancer), EVSA‐T (mammary cancer), WiDr (colon cancer), IGROV (ovarian cancer), M19 MEL (melanoma), A498 (renal cancer) and H226 (lung cancer) cell lines. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

19.
The sluggish sodium reaction kinetics, unstable Sn/Na2O interface, and large volume expansion are major obstacles that impede practical applications of SnO2‐based electrodes for sodium‐ion batteries (SIBs). Herein, we report the crafting of homogeneously confined oxygen‐vacancy‐containing SnO2?x nanoparticles with well‐defined void space in porous carbon nanofibers (denoted SnO2?x/C composites) that address the issues noted above for advanced SIBs. Notably, SnO2?x/C composites can be readily exploited as the working electrode, without need for binders and conductive additives. In contrast to past work, SnO2?x/C composites‐based SIBs show remarkable electrochemical performance, offering high reversible capacity, ultralong cyclic stability, and excellent rate capability. A discharge capacity of 565 mAh g?1 at 1 A g?1 is retained after 2000 cycles.  相似文献   

20.
Bis‐β‐ketoimine ligands of the form [(CH2)n{N(H)C(Me)?CHC(Me)?O}2] (LnH2, n=2, 3 and 4) were employed in the formation of a range of gallium complexes [Ga(Ln)X] (X=Cl, Me, H), which were characterised by NMR spectroscopy, mass spectrometry and single‐crystal X‐ray diffraction analysis. The β‐ketoimine ligands have also been used for the stabilisation of rare gallium hydride species [Ga(Ln)H] (n=2 ( 7 ); n=3 ( 8 )), which have been structurally characterised for the first time, confirming the formation of five‐coordinate, monomeric species. The stability of these hydrides has been probed through thermal analysis, revealing stability at temperatures in excess of 200 °C. The efficacy of all the gallium β‐ketoiminate complexes as molecular precursors for the deposition of gallium oxide thin films by chemical vapour deposition (CVD) has been investigated through thermogravimetric analysis and deposition studies, with the best results being found for a bimetallic gallium methyl complex [L3{GaMe2}2] ( 5 ) and the hydride [Ga(L3)H] ( 8 ). The resulting films ( F5 and F8 , respectively) were amorphous as‐deposited and thus were characterised primarily by XPS, EDXA and SEM techniques, which showed the formation of stoichiometric ( F5 ) and oxygen‐deficient ( F8 ) Ga2O3 thin films.  相似文献   

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