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1.
Thin films of molybdenum oxide were formed on glass and silicon substrates by sputtering of molybdenum target under various
sputtering powers in the range 2.3–6.8 W/cm2, at a constant oxygen partial pressure of 2 × 10−4 mbar and substrate temperature 523 K employing DC magnetron sputtering technique. The effect of sputtering power on the core
level binding energies, chemical binding configurations, crystallographic structure, surface morphology and electrical and
optical properties was systematically studied. X-ray photoelectron spectroscopic studies revealed that the films formed at
sputtering powers less than 5.7 W/cm2 were mixed oxidation states of Mo5+ and Mo6+. The films formed at 5.7 W/cm2 contained the oxidation state Mo6+ of MoO3. Fourier transform infrared spectra contained the characteristic optical vibrations. The presence of a sharp absorption band
at 1,000 cm−1 in the case of the films formed at 5.7 W/cm2 was also conformed the existence of α-phase MoO3. X-ray diffraction studies also confirmed that the films formed at sputtering powers less than 5.7 W/cm2 showed the mixed phase of α-and β-phase of MoO3 where as at sputtering power of 5.7 W/cm2 showed single phase α-MoO3. The electrical conductivity of the films increased from 8 × 10−6 to 1.2 × 10−4 Ω−1 cm−1, the optical band gap decreased from 3.28 to 3.12 eV and the refractive index decreased from 2.12 to 1.94 with the increase
of sputtering power from 2.3 to 6.8 W/cm2, respectively. 相似文献
2.
3.
Transparent films of copper yttrium oxide doped with 2% calcium have been prepared by rf magnetron sputtering. The films show
a conductivity of 8 Scm−1 on intercalation of oxygen at high pressure, which reduced the transparency in the visible region. The Ca-doped CuYO2 films before oxygen intercalation show an average transmission of about 60% which reduces to about 45% upon oxygen intercalation.
The temperature dependence of the conductivity indicates semiconductor behaviour with low activation energy of 0·59 eV at
room temperature. The positive sign of Seebeck coefficient (+274 μVK−1) confirms the p-type conductivity of the films. The optical bandgap of CuYO2 was found to be 3·15 eV. 相似文献
4.
A. Sivasankar Reddy P. Sreedhara Reddy S. Uthanna G. Mohan Rao 《Journal of Materials Science: Materials in Electronics》2006,17(8):615-620
Thin films of copper aluminum oxide (CuAlO2) were prepared on glass substrates by dc magnetron sputtering at a substrate temperature of 523 K under various oxygen partial
pressures in the range 1 × 10−4–3 × 10−3 mbar. The dependence of cathode potential on the oxygen partial pressure was explained in terms of oxidation of the sputtering
target. The influence of oxygen partial pressure on the structural, electrical and optical properties was systematically studied.
p-Type CuAlO2 films with polycrystalline nature, electrical resistivity of 3.1 Ω cm, Hall mobility of 13.1 cm2 V−1 s−1 and optical band gap of 3.54 eV were obtained at an oxygen partial pressure of 6 × 10−4 mbar. 相似文献
5.
Meng Wang Jianjun Li Qiang Lei Jun Yu Wenli Zhou 《Journal of Materials Science: Materials in Electronics》2011,22(8):1033-1039
Ba0.6Sr0.4TiO3 films were fabricated by RF magnetron sputtering method. The X-ray diffraction (XRD) showed that the preferred orientation
of films growing on platinum Si substrates can be tailored by sputtering pressure. The processing parameters such as sputtering
pressure and substrate temperature were optimized to obtain a developed perovskite film with (110) preferred orientation.
The polarization hysteresis loops and permittivity–voltage curves of the (110)-oriented film have been investigated,which
demonstrated that the film is in ferroelectric phase at room temperature. Besides, it had excellent fatigue properties without
polarization reduction after about 1010 switch cycles, and showed low leakage current (10−9–10−7 A/cm2) within an applied voltage of 5 V. Finally, the leakage current mechanism was studied. 相似文献
6.
Al:ZnO (AZO) films were deposited on glass substrate with inborn surface texture by magnetron sputtering at a power density
as high as 7 W/cm2. The sputtering parameters, such as argon working pressure and substrate temperature were varied from 1.0 to 6.0 Pa and from
room temperature to 500 °C, respectively. All the films exhibited perfect (002) orientations with very weak (004) peaks measured
by X-ray diffraction. A linear relationship between the growth rate of AZO film and working pressure was found. The AZO film
with best electrical properties of all films obtained at room temperature was deposited at working pressure of 2.0 Pa. And
the root-mean-square roughness tested by atomic force microscopy was 37.50 nm, which indicated that surface texture was successfully
fabricated without further etching process. For higher substrate temperature a decrease in the resistivity was observed due
to an increase in the mobility and the carrier concentration. Resistivity low as 9.044 × 10−4 ohm/cm was obtained at 500 °C and 2.0 Pa, the corresponding mobility and carrier concentration were 20.45 m2/Vs and 3.379 × 1020/cm3, respectively. The grain size and the surface texture size tested by scanning electron microscopy also peaked at 500 °C.
All the films showed a relatively high transmittance about 80%. 相似文献
7.
Fatigue-free bismuth-layered SrBi2Ta2O9 (SBT) films were deposited on Pt/Ti/SiO2/Si substrates by r.f. magnetron sputtering at room temperature. The variation of structure and electrical properties were studied as a function of annealing temperatures from 750–850 °C. The films annealed at 800 °C had a composition ratio of Sr:Br:Ta = 0.7:2.0:2.0. X-ray photoelectron spectroscopy signals of bismuth show an oxygen-deficient state within the SBT films. The films annealed at 800 °C have a thickness of 200 nm and a relatively dense microstructure. The remanent polarization (2P
r), and the coercive field (2E
c), obtained for the SIBT films, were 9.1 C cm–2 and 85 kV cm–1 at an applied voltage of 3 V, respectively. The films showed fatigue-free characteristics up to 1010 cycles under 5 V bipolar square pulses. The leakage current density was about 7 × 10–7 A cm–2 at 150 kV cm–1. The SBT films prepared by r.f. magnetron sputtering were attractive for application to non-volatile memories. 相似文献
8.
Influence of deposition parameters on preferred orientation of RF magnetron sputtered BST thin films
Songzhan Li Yanqin Yang L. Liu T. J. Zhang W. H. Huang 《Journal of Materials Science: Materials in Electronics》2008,19(3):223-226
Ba0.65Sr0.35TiO3 (BST) thin films have been deposited by radio frequency magnetron sputtering. The effects of the deposition parameters on
the crystallization and microstructure of BST thin films were investigated by X-ray diffraction and field emission scanning
electron microscopy, respectively. The crystallization behavior of these films was apparently affected by the substrate temperature,
annealing temperature and sputtering pressure. The as-deposited thin films at room temperature were amorphous. However, the
improved crystallization is observed for BST thin films deposited at higher temperature. As the annealing temperature increased,
the dominant X-ray diffraction peaks became sharper and more intense. The dominant diffraction peaks increased with the sputtering
pressures increasing as the films deposited at 0.37–1.2 Pa. With increasing the sputtering pressure up to 3.9 Pa, BST thin
films had the (110) + (200) preferred orientation. Possible correlations of the crystallization with changes in the sputtering
pressure were discussed. The SEM morphologies indicated the film was small grains, smooth, and the interface between the film
and the substrate was sharp and clear. 相似文献
9.
Diamond-like carbon (DLC) film is a promising candidate for surface acoustic wave (SAW) device applications because of its higher acoustic velocity. A zinc oxide (ZnO) thin film has been deposited on DLC film/Si substrate by RF magnetron sputtering; the optimized parameters for the ZnO sputtering are RF power density of 0.55 W/cm2, substrate temperature of 380 °C, gas flow ratio (Ar/O2) of 5/1 and total sputter pressure of 1.33 Pa. The results showed that when the thickness of the ZnO thin films was decreased, the phase velocity of the SAW devices increased significantly. 相似文献
10.
Transparent PZT thin films with perovskite structure were successfully obtained by thermal decomposition of organometallic
compounds at the temperatures of 500 to 700° C. The films deposited on platinum substrates were smooth and uniform, but microcrackings
were observed in the films deposited on fused silica substrates. The ratio of metal composition in the PZT film agreed with
that in the mixture of starting materials. Films obtained at 700° C on platinum substrate showed a hysteresis loop. A spontaneous
polarization was 35.65μC cm−2, a saturation remanent polarization was 30.56μC cm−2 and a coercive field was 45 kV cm−1. Dielectric constant and dielectric loss angle were about 300 and 0.05, respectively. 相似文献
11.
S.P. Murarka 《Thin solid films》1974,23(3):323-336
Platinum films have been deposited using the technique of r.f. sputtering. The properties of the sputtered films were studied as a function of experimental sputtering power, ambient gas pressure, substrate temperature and bias. As a result of these studies it was possible to deposit platinum films of resistivity as low as approximately 13 μΩcm. It was found that the stress in these films can be varied from about 5x109 dyn/cm2 compressive to about 5x109 dyn/cm2 tensile depending upon the deposition conditions. 相似文献
12.
The microstructure development of SnO2·CuO based ceramic material was analyzed by XRD and SEM and the electrical properties were investigated by J-E relation. The secondary phases of copper oxide were found by the XRD. Copper oxide could make tin oxide densify and advance
the grain growth, while tantalum oxide would retard the grain growth. Excess copper would centralize at the grain boundaries
and prevent the mass transport. The high nonlinear coefficient (α = 27.3) and low leakage current density (JL = 16 μA cm−2) for the 0.05 mol% Ta2O5-doped SnO2·CuO based varistor sample were obtained. The modified defect barrier model for CuO and Ta2O5-doped SnO2 based varistors was introduced. 相似文献
13.
M. C. Kao H. Z. Chen S. L. Young C. Y. Kung C. C. Lin J. Z. Lai 《Journal of Superconductivity and Novel Magnetism》2010,23(6):897-900
Nanocrystalline ZnO thin films were prepared by the sol–gel method and annealed at 600 °C by conventional (CTA) and rapid
thermal annealing (RTA) processes on fluorine-doped tin oxide (FTO)-coated glass substrates for application as the work electrode
for a dye-sensitized solar cell (DSSC). ZnO films were crystallized using a conventional furnace and the proposed RTA process
at annealing rates of 5 °C/min and 600 °C/min, respectively. The ZnO thin films were characterized by X-ray diffraction (XRD)
and atomic force microscopy (AFM) analyses. Based on the results, the ZnO thin films crystallized by the RTA process presented
better crystallization than films crystallized in a conventional furnace. The ZnO films crystallized by RTA showed higher
porosity and surface area than those prepared by CTA. The results show that the short-circuit photocurrent (J
sc) and open-circuit voltage (V
oc) values increased from 4.38 mA/cm2 and 0.55 V for the DSSC with the CTA-derived ZnO films to 5.88 mA/cm2 and 0.61 V, respectively, for the DSSC containing the RTA-derived ZnO films. 相似文献
14.
R D Vispute R R Rao Sucheta Gorwadkar S A Gangal S B Ogale 《Bulletin of Materials Science》1992,15(4):377-384
Superconducting thin films of Y1Ba2Cu3 O7 −x
have been deposited on (100) Y-ZrO2 substrates by pulsed excimer laser ablation from anunreacted mixture of Y2O3, BaCO3 and CuO. The films deposited at substrate temperature of 680°C and oxygen partial pressure of 200 mtorr were found to be
superconducting with zero resistive transition temperature of 89 K and critical current density of over 3 × 105 A/cm2 at 77 K. These results are compared with those obtained by laser ablation from a sintered superconducting pellet. 相似文献
15.
Youl-Moon Sung 《Thin solid films》2007,515(12):4996-4999
Sputter deposition followed by surface treatment was studied using reactive RF plasma as a method for preparing titanium oxide (TiO2) films on indium tin oxide (ITO) coated glass substrate for dye-sensitized solar cells (DSCs). Anatase structure TiO2 films deposited by reactive RF magnetron sputtering under the conditions of Ar/O2(5%) mixtures, RF power of 600 W and substrate temperature of 400 °C were surface-treated by inductive coupled plasma (ICP) with Ar/O2 mixtures at substrate temperature of 400 °C, and thus the films were applied to the DSCs. The TiO2 films made on these experimental bases exhibited the BET specific surface area of 95 m2/g, the pore volume of 0.3 cm2/g and the TEM particle size of ∼ 25 nm. The DSCs made of this TiO2 material exhibited an energy conversion efficiency of about 2.25% at 100 mW/cm2 light intensity. 相似文献
16.
Sookjoo Kim Wan In Lee El-Hang Lee S. K. Hwang Chongmu Lee 《Journal of Materials Science》2007,42(13):4845-4849
Ga-doped ZnO (GZO) thin films were prepared by rf magnetron sputtering and dependence of the electrical resistivity and the
transmittance of the GZO films on the oxygen partial pressure (R = the O2/Ar gas flow ratio) and the substrate temperature were investigated. The resistivity of the GZO film decreases first and then
increases with an increase in the substrate temperature (T). A minimum resistivity obtained with a substrate temperature of
300 °C is 3.3 × 10−4 Ωcm. The resistivity nearly does not change with R for R < 0.25. The decrease in the resistivity for R < 0.25 is attributed to enhancement in crystallinity, whereas the increase in the resistivity for R > 0.25 to precipitation of gallium oxides at grain boundaries. Optical transmittance of the GZO films is enhanced by increasing
R up to 0.75. This enhancement in the transmittance is due to a decrease in oxygen vacancy concentration and a decrease in
surface roughness with R. 相似文献
17.
K. J. Patel M. S. Desai C. J. Panchal 《Journal of Materials Science: Materials in Electronics》2011,22(8):959-965
Indium tin oxide (ITO) thin films were deposited by radio frequency (RF) magnetron sputtering onto glass substrates. The transparent
and conducting ITO thin films were obtained on externally unheated glass substrate, without any post-heat treatment, and by
varying the deposition process parameters such as the working pressure and the RF Power. The effect of the variation of the
above deposition parameters on the structural, surface morphology, electrical, and optical properties of the thin films have
been studied. A minimum resistivity of 2.36 × 10−4 Ω cm and 80% transmittance with a figure of merit 37.2 × 10−3 Ω−1 is achieved for the thin films grown on externally unheated substrate with 75 W RF power and 0.5 mTorr working pressure. 相似文献
18.
Jung-Min Kim 《Thin solid films》2010,518(20):5860-1267
100 nm Al-doped ZnO (AZO) thin films were deposited on polyethylene naphthalate (PEN) substrates with radio frequency magnetron sputtering using 2 wt.% Al-doped ZnO target at various deposition conditions including sputtering power, target to substrate distance, working pressure and substrate temperature. When the sputtering power, target to substrate distance and working pressure were decreased, the resistivity was decreased due to the improvement of crystallinity with larger grain size. As the substrate temperature was increased from 25 to 120 °C, AZO films showed lower electrical resistivity and better optical transmittance due to the significant improvement of the crystallinity. 2 wt.% Al-doped ZnO films deposited on glass and PEN substrates at sputtering power of 25 W, target to substrate distance of 6.8 cm, working pressure of 0.4 Pa and substrate temperature of 120 °C showed the lowest resistivity (5.12 × 10− 3 Ω cm on PEN substrate, 3.85 × 10− 3 Ω cm on glass substrate) and high average transmittance (> 90% in both substrates). AZO films deposited on PEN substrate showed similar electrical and optical properties like AZO films deposited on glass substrates. 相似文献
19.
Wenjian Leng Chuanren Yang Hong Ji Jihua Zhang Jinlong Tang Hongwei Chen 《Journal of Materials Science: Materials in Electronics》2006,17(12):1041-1045
Ferroelectric (Pb0.92La0.08)(Zr0.65Ti0.35)O3 (PLZT) films have been prepared on Pt/Ti/SiO2/Si and fused quartz substrates using radio-frequency (rf) magnetron sputtering at a deposition temperature of 650°C. X-ray diffraction analysis shows that the PLZT thin films on platinized silicon are polycrystalline with (100)-preferential orientation. A Al/PLZT/Pt capacitor has been fabricated and it shows that the films have excellent ferroelectric character, with saturation polarization (P
s), remanent polarization (P
r) and coercive field (E
c) of 32.8μC/cm2, 24.3μC/cm2 and 142 kV/cm, respectively. The PLZT thin films exhibit good insulating property and the leakage current density of the films on platinized silicon is only about 0.86 × 10−7 A/cm2 at 200 kV/cm. By the optical transmission spectra measurements, the energy gap (E
g) of the PLZT films on fused quartz is found to be about 3.54 eV. The optical constants (n and k) of the films in the wavelength range of 250–900 nm are obtained by a Filmetrics F20 reflectance spectrometer. 相似文献
20.
Transparent conducting ZnO:F was deposited as thin films on soda lime glass substrates by atmospheric pressure chemical vapor
deposition (CVD) deposition at substrate temperatures of 480–500 °C. The precursors diethylzinc, tetramethylethylenediamine
and benzoyl fluoride were dissolved in xylene. The solution was nebulized ultrasonically and then flash vaporized by a carrier
gas of nitrogen preheated to 150 °C. Ethanol was vaporized separately, and these vapors were then mixed to form a homogeneous
vapor mixture. Good reproducibility was achieved using this new CVD method. Uniform thicknesses were obtained by moving the
heated glass substrates through the deposition zone. The best electrical and optical properties were obtained when the precursor
solution was aged for more than a week before use. The films were polycrystalline and highly oriented with the c-axis perpendicular to the substrate. The electrical resistivity of the films was as low as 5 × 10−4 Ωcm. The mobility was about 45 cm2/Vs. The electron concentration was up to 3 × 1020/cm3. The optical absorption of the films was about 3–4% at a sheet resistance of 7 Ω/square. The diffuse transmittance was about
10% at a thickness of 650 nm. Amorphous silicon solar cells were deposited using the textured ZnO:F films as the front electrode.
The short circuit current was increased over similar cells made with fluorine doped tin oxide, but the voltages and fill factors
were reduced. The voltage was restored by overcoating the ZnO:F with a thin layer of SnO2:F. 相似文献