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1.
We have fabricated a LPG and butane sensor whose sensitive element is a nanosize In 2O 3:Ga 2O 3 (96:4 weight %) film covered with a thin palladium catalytic layer. Technology of deposition of these films on a glassceramic substrate by the method of rf magnetron sputtering was elaborated. The surfaces of fabricated films were studied with use of a scanning electron microscope and the thickness of films was measured. The sensitivity of sensors based on the glassceramic/In 2O 3:Ga 2O 3 (96:4 weight %)/Pd structure depending on the thickness and sizes of film grains was studied. We revealed technological regimes of sputtering providing fabrication of films with the best parameters. 相似文献
2.
We study in detail the potential energy surface of Ga and Sr substituted Ba 2In 2O 5 by considering the changes in the relative energies of the local structures of Ba 2In 2O 5 when replacing 1 / 8th of the indium atoms with gallium or 1 / 8th of the barium atoms with strontium. The calculations are subsequently used to interpret the increase in ionic conductivity of cubic Ba 2In 2O 5 when strontium is substituted for barium and the decrease in ionic conductivity when gallium is substituted for indium. The effects of replacing 1 / 8th of the indium atoms with gallium or 1 / 8th of the barium atoms with strontium are significant and affect considerably the relative stability of the different low energy local structures present for Ba 2In 2O 5. While a higher density of low energy structures is observed for Ba 1.75Sr 0.25In 2O 5 than for Ba 2In 2O 5, the opposite occurs for Ba 2In 1.75Ga 0.25O 5. This observation supports our main hypothesis: a high density of low energy local structures is a prerequisite for high ionic conductivity. 相似文献
3.
In 2O 3 nanowires functionalized with Fe 2O 3 nanoparticles were synthesized by the thermal evaporation of In 2S 3 powders in an oxidizing atmosphere followed by the solvothermal deposition of Fe 2O 3 and their acetone gas sensing properties were examined. The pristine and Fe 2O 3-functionalized In 2O 3 nanowires exhibited responses of 141–390% and 298–960%, respectively, to 10–500 ppm acetone at 200 °C. The Fe 2O 3-functionalized In 2O 3 nanowire sensor showed stronger electrical response to acetone gas at 200 °C than the pristine In 2O 3 nanowire counterpart. The former showed more rapid response but slower recovery than the latter. Both the pristine and Fe 2O 3-functionalized In 2O 3 nanowire sensors showed the strongest response to acetone gas at 200 °C. The underlying mechanism for the enhanced sensing performance of the Fe 2O 3-functionalized In 2O 3 nanowire sensor towards acetone gas is discussed. 相似文献
4.
This paper reports the facile synthesis of In 2O 3-capped Zn-doped Fe 2O 3 nanorods along with their ethanol gas sensing properties. A two-stage process involving thermal oxidation of Fe foils and Zn powders in air and the sputter-deposition of In 2O 3 was used to synthesize these nanostructures. The nanorods synthesized using this method were ∼5 μm in length and 50–120 nm in diameter with a shell layer thickness of 10–15 nm. The multiple-networked In 2O 3-capped Zn-doped Fe 2O 3 nanorod sensor showed a significantly enhanced and ultrafast response to ethanol gas. The enhanced sensing performance was explained by modulation of the potential barrier height and the strong catalytic activity of In 2O 3 for ethanol oxidation. 相似文献
5.
The presence of an AlN interfacial layer in high-k/In 0.53Ga 0.47As gate stacks improves the interfacial properties and enhances the electrical performance of devices. However, pure AlN is rarely grown by atomic layer deposition (ALD) because of the low reactivity of NH 3 toward the common Al-precursor and the predisposition to oxidation of the grown AlN layer. Although a plasma-enhanced ALD technique significantly suppresses the oxygen content in the grown AlN layer, the deterioration of the interface properties by plasma-damage is a critical issue. In this work, an AlON interlayer was engineered by optimizing the NH 3 feeding time in thermal ALD to improve the interface quality in Al 2O 3/AlON/In 0.53Ga 0.47As capacitors. It was determined that a mere increase in the NH 3 feeding time during the ALD of the AlON film resulted in a higher nitrogen incorporation into the AlON interlayer, leading to a reduction in the interface trap density. Furthermore, the out-diffusion of elements from the In 0.53Ga 0.47As layer was effectively suppressed by increasing the NH 3 feeding time. This work demonstrates that simple process optimization can improve the interface quality in high-k/In 0.53Ga 0.47As gate stacks without the use of any plasma-activated nitrogen source. 相似文献
6.
We report highly transparent Ag-doped In 2O 3 (IAO) films with high work function for use as transparent anodes in organic solar cells (OSCs). The electrical, optical, structural, and morphological properties of IAO films and their work function were investigated as a function of the rapid thermal annealing (RTA) temperature. At an RTA temperature of 600 °C, the IAO film showed a sheet resistance of 23.12 Ohm/square, an optical transmittance of 79.28%, and a work function of 5.21 eV, similar to conventional Sn-doped In 2O 3 (ITO) films. The low resistivity of the IAO film was closely related to oxygen vacancies caused by Ag suboxide formation in the In 2O 3 matrix. A bulk-heterojunction OSC with the optimized IAO anode showed performance comparable to that of an OSC with a reference ITO anode, indicating that the IAO films is a promising anode material for use in OSCs. 相似文献
7.
SnO 2-core/In 2O 3-shell nanobelts were fabricated by a two-step process comprising thermal evaporation of Sn powders and sputter-deposition of In 2O 3. Transmission electron microscopy and X-ray diffraction analyses revealed that the core of a typical core–shell nanobelt comprised a simple tetragonal-structured single crystal SnO 2 and that the shell comprised an amorphous In 2O 3. Multiple networked SnO 2-core/In 2O 3-shell nanobelt sensors showed the response of 5.35% at a NO 2 concentration of 10 ppm at 300 °C. This response value is more than three times larger than that of bare-SnO 2 nanobelt sensors at the same NO 2 concentration. The enhancement in the sensitivity of SnO 2 nanobelts to NO 2 gas by sheathing the nanobelts with In 2O 3 can be accounted for by the modulation of electron transport by the In 2O 3–In 2O 3 homojunction. 相似文献
8.
Ni-based cermets were prepared and reduced from mixtures of NiO and Ba 2In 0.6Ti 1.4O 5.7□ 0.3. A cermet containing 18.7 vol.% of Ni exhibits promising characteristics: 40% of open porosity and a lower DC resistivity than a Ni/YSZ cermet with a larger Ni content (30 vol.%). Its thermal expansion coefficient is 11.4 × 10 − 6 K − 1 whereas that measured for Ba 2In 0.6Ti 1.4O 5.7□ 0.3 is 9.9 × 10 − 6 K − 1. Electrical measurements vs. the Ni content have shown that the percolation threshold corresponds to 15.7 vol.% of Ni. By using saccharose as a pore former, the porosity of the electrode can be tuned. It is shown that the pore size is controlled by the particle size distribution of the pore former. 相似文献
9.
The timing characteristics of scintillation response of Czochralski-grown Gd 3Al 2Ga 3O 12:Ce and Gd 3Al 2.6Ga 2.4O 12:Ce single crystals were compared. The photoelectron yield, scintillation decay times, and coincidence time resolution were measured. At 662 keV γ-rays, the photoelectron yield of 6200 phe MeV −1 obtained for Gd 3Al 2Ga 3O 12:Ce is higher than that of 4970 phe MeV −1 obtained for Gd 3Al 2.6Ga 2.4O 12:Ce, while an inferior energy resolution of the former (7.2% vs. 5.6%) is observed. Scintillation decays are approximated by sum of exponentials with the dominant fast component decay time and its relative intensity of 89 ns (73%) for Gd 3Al 2Ga 3O 12:Ce and 136 ns (69%) for Gd 3Al 2.6Ga 2.4O 12:Ce. The coincidence time resolution obtained for Gd 3Al 2Ga 3O 12:Ce is superior than that of Gd 3Al 2.6Ga 2.4O 12:Ce. The normalized time resolution was also discussed in terms of a number of photoelectrons and decay characteristics of the light pulse. 相似文献
10.
In this study, we proposed ‘switching ultrasonic amplitude’ as a new strategy of applying ultrasonic energy to prepare a hybrid of buckminsterfullerene (C 60) and gallium oxide (Ga 2O 3), C 60/Ga 2O 3. In the proposed method, we switched the ultrasonic amplitude from 25% to 50% (by 5% amplitude per 10 min, within 1 h of ultrasonic irradiation) for the sonochemical treatment of a heterogeneous aqueous mixture of C 60 and Ga 2O 3 by a probe-type ultrasonic horn operating at 20 kHz. We found that compared to the conventional techniques associated with high amplitude oriented ultrasonic preparation of functional materials, switching ultrasonic amplitude can better perform in preparing C 60/Ga 2O 3 with respect to avoiding titanium (Ti) as an impurity generating from the tip erosion of a probe-type ultrasonic horn during high amplitude ultrasonic irradiation in an aqueous medium. Based on SEM/EDX analysis, the quantity of Ti (wt.%) in C 60/Ga 2O 3 prepared by the proposed technique of switching ultrasonic amplitude was found to be 1.7% less than that prepared at 50% amplitude of ultrasonic irradiation. The particles of C 60/Ga 2O 3 prepared by different modes of amplitude formed large (2–12 μm) aggregates in their solid phase.Whereas, in the aqueous medium, they were found to disperse in their nano sizes. The minimum particle size of the as-synthesized C 60/Ga 2O 3 in an aqueous medium prepared by the proposed method of switching ultrasonic amplitude reached to approximately 467 nm. Comparatively, the minimum particle sizes were approximately 658 nm and 144 nm, using 25% and 50% amplitude, respectively. Additionally, Ga 2O 3 went under hydration during ultrasonic irradiation. Moreover, due to the electron cloud interference from C 60 in the hybrid structure of C 60/Ga 2O 3, the vibrational modes of Ga 2O 3 were Raman inactive in C 60/Ga 2O 3. 相似文献
11.
Sn-doped Ga 1.4In 0.6O 3 films have been prepared on α-Al 2O 3 (0 0 0 1) substrates by the metalorganic chemical vapor deposition (MOCVD) method. The Sn-doping was varied from 0% to 7% (atomic ratio). Polycrystalline films with resistivity of 4.9 × 10 −3Ω cm, carrier concentration of 5.9 × 10 19 cm −3 and Hall mobility of 21.4 cm 2 v −1 s −1 was obtained at 5 at.% of Sn concentration. The average transmittance for the Sn-doped Ga 1.4In 0.6O 3 films in the visible range was over 90%. The bandgap of the films varies from 3.85 to 4.21 eV. 相似文献
12.
This study focuses on the influence of loading MWCNTs in In2O3-based DSSCs. In2O3-MWCNTs were prepared by sol-gel method via spin coating technique and annealed at 450 °C. The structural, morphology, and electrical properties of the photoanodes were characterized by means of XRD, AFM and FESEM, and J-V curve measurement and EIS properties, respectively. Incorporation of MWCNTs in In2O3 improved the J
sc
and V
oc
of the cell. However, excess loading of MWCNTs in In2O3 caused a serious aggregation of MWCNTs that increased the recombination rate. Thus, In2O3-MWCNTs with 0.3 % of MWCNTs achieved the highest PCE of 1.23 % with large surface area for efficient dye adsorption. Moreover, In2O3-MWCNTs(0.3%) exhibited large D
eff about 25.7 × 10−3 cm2 s−1 with low recombination effect that increased the PCE. This study suggests an optimum MWCNT incorporation of 0.3 % in the photoanode by sol-gel synthesis method of developing In2O3-based nanocomposite. 相似文献
13.
Mo-doped In 2O 3 thin films have been prepared on glass substrates using an activated reactive evaporation method and systematically studied the effect of oxygen partial pressure on the structural, optical, electrical and photoluminescence properties of the films. The obtained films are highly transparent and conductive. The films exhibited the lowest electrical resistivity of 5.2 × 10 −4 Ω cm, with an average optical transmittance of 90% in the visible region. An intensive photoluminescence emission peaks were observed at 415 and 440 nm. 相似文献
14.
Large-area In 2O 3 ordered pore arrays were prepared on glass and silicon substrates by the sol–gel technique based on colloidal monolayer spheres. The morphologies of such arrays are determined by precursor concentration used and colloidal sphere size, and are thus controllable. It has been shown that the formed ordered pore arrays consist of In 2O 3 polycrystallites. The photoluminescence measurement of the In 2O 3 ordered pore arrays shows that there is a strong photoluminescence band in the blue-green region centered around 465 nm, which does not exist in the bulk materials. Further experiments reveal that this peak originates from the oxygen deficiencies in In 2O 3 skeletons. This polydomain ordered pore-structured array could be of great potential for Si-based integrated nanophotonics and optoelectronic devices of the next generation, in addition to new gas sensors. PACS 01.30.-y; 78.20.-e; 78.55.-m; 78.55.Et 相似文献
15.
We have synthesized monoclinic gallium oxide (βGa 2O 3) nanowires on Au-coated Si substrates by a reaction of a trimethylgallium and oxygen mixture. The βGa 2O 3 nanowires became progressively thinner from bottom to top, with diameters ranging from 10 to 200 nm and lengths of several micrometers. We found that Au-containing nanoparticles were attached to the tips of the βGa 2O 3 nanowires and thus the nanowire growth could be a vapor–liquid–solid process .PACS 81.07.-b; 81.15.Gh 相似文献
16.
New series of oxides, La 3MMo 2O 12 (M = In, Ga and Al), have been prepared by the solid-state reaction. The composition and elemental distribution were analyzed by the energy-dispersive X-ray (EDX) analysis. As determined by the X-ray diffraction (XRD), these compounds have similar crystal structures that can be indexed on a monoclinic cell at room temperature. AC impedance spectra and the DC electrical conductivity measurements in various atmospheres indicate that they are oxide ion conductors with ionic conductivities between 10 − 2 and 10 − 3 S/cm at 800 °C. The conductivity decreases in the order of La 3GaMo 2O 12 > La 3AlMo 2O 12 > La 3InMo 2O 12, implying that the effect of cell volume and polarization associated with In 3+, Ga 3+ and Al 3+ play an important role in the anion transport of these materials. The reversible phase transition was observed in all these compounds as confirmed by the differential thermal analysis (DTA) and dilatometric measurements. 相似文献
17.
Monodisperse indium oxide (In 2O 3) nanoparticles (NPs) with the average diameter of 11 nm were prepared by a solvothermal method. The In 2O 3 NPs were characterized by X-ray diffraction, Raman and transmission electron microscopy. The intrinsic nature of ferromagnetism in In 2O 3 NPs has been established with the experimental observation of magnetic hysteresis loop. Photoluminescence and UV–visible studies were employed to evidence the presence of oxygen vacancies and revealed that the oxygen vacancies contribute to the ferromagnetism. The origin of ferromagnetism in In 2O 3 NPs may be due to exchange interactions among localized electron spin moments resulting from oxygen vacancies. 相似文献
18.
The concentration-dependent luminescence properties of sol–gel-derived nanocrystalline Lu 3(1?x)Er 3xGa 5O 12 powders (where x=0.01, 0.05 and 0.1) have been studied. Laser-excited luminescence spectra, emission decays and upconversion luminescence of Er 3+-doped Lu 3Ga 5O 12 nanocrystalline samples have been measured. The decay curve of the ( 2H 11/2, 4S 3/2) emission exhibits a non-exponential behavior presumably due to cross-relaxation process. Moreover, near-infrared to visible upconversion luminescence has been observed in the green region for 1.0 mol% Er 3+ ions in Lu 3Ga 5O 12 nanocrystals upon 815 nm excitation. The power dependence of the anti-Stokes luminescence suggests that upconversion is probably achieved through the sequential absorption of two photons. To the best of our knowledge, this is the first report on the preparation and optical properties of Er 3+-doped Lu 3Ga 5O 12 in the form of nanocrystalline powders. 相似文献
19.
Zinc-blende-type face centred cubic structure GaP nanowires with Ga 2O 3 coating were synthesized by heating Ga 2O 3 and red phosphorus powder with the assistance of NH 3 and Ar at 1323 K. The GaP/Ga 2O 3 nanowires have a uniform size distribution with diameters ranging from tens of nm to hundreds of nm and lengths up to several micrometres. The inner GaP nanowires have almost a single-crystal structure with twin defects and have the 111 direction as preferential growth direction. Outer Ga 2O 3 layers were polycrystalline and acted as a protection layer for the inner GaP nanowires to permit their use at high temperature. The GaP/Ga 2O 3 structure may have potential applications in future nanodevice design. PACS 81.07.Bc; 81.16.Pr 相似文献
20.
The structural and electronic properties of group III rich In 0.53Ga 0.47As(001) have been studied using scanning tunneling microscopy/spectroscopy (STM/STS). At room temperature (300 K), STM images show that the In 0.53Ga 0.47As(001)–(4 × 2) reconstruction is comprised of undimerized In/Ga atoms in the top layer. Quantitative comparison of the In 0.53Ga 0.47As(001)–(4 × 2) and InAs(001)–(4 × 2) shows the reconstructions are almost identical, but In 0.53Ga 0.47As(001)–(4 × 2) has at least a 4× higher surface defect density even on the best samples. At low temperature (77 K), STM images show that the most probable In 0.53Ga 0.47As(001) reconstruction is comprised of one In/Ga dimer and two undimerized In/Ga atoms in the top layer in a double (4 × 2) unit cell. Density functional theory (DFT) simulations at elevated temperature are consistent with the experimentally observed 300 K structure being a thermal superposition of three structures. DFT molecular dynamics (MD) show the row dimer formation and breaking is facilitated by the very large motions of tricoodinated row edge As atoms and z motion of In/Ga row atoms induced changes in As–In/Ga–As bond angles at elevated temperature. STS results show there is a surface dipole or the pinning states near the valence band (VB) for 300 K In 0.53Ga 0.47As(001)–(4 × 2) surface consistent with DFT calculations. DFT calculations of the band-decomposed charge density indicate that the strained unbuckled trough dimers being responsible for the surface pinning. 相似文献
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