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1.
BingQing Zhou MeiFang Zhu FengZhen Liu JinLong Liu YuQin Zhou GuoHua Li Kun Ding 《中国科学E辑(英文版)》2008,51(4):371-377
Hydrogenated microcrystalline silicon (μc-Si:H) thin films were prepared by high-pressure radio-frequency (13.56 MHz) plasma
enhanced chemical vapor deposition (rf-PECVD) with a screened plasma. The deposition rate and crystallinity varying with the
deposition pressure, rf power, hydrogen dilution ratio and electrodes distance were systematically studied. By optimizing
the deposition parameters the device quality μc-Si:H films have been achieved with a high deposition rate of 7.8 ?/s at a
high pressure. The V
oc of 560 mV and the FF of 0.70 have been achieved for a single-junction μc-Si:H p-i-n solar cell at a deposition rate of 7.8
?/s.
Supported by the National Natural Science Foundation of China (Grant No. 50662003) and the State Development Program for Basic
Research of China (Grant No. G2000028208) 相似文献
2.
YANG Weiming YU Jun HE Linxiang ZHOU Shen YANG Guang 《武汉理工大学学报(材料科学英文版)》2007,22(4):634-637
(Ba0.4Pb0.3)Sr0.3TiO3 thin films were fabricated via pulsed laser deposition (PLD) technique on Pt/TiO2/SiO2/Si substrate. The crystallization of the films was characterized by XRD and FSEM, and the experimental results suggested deposition parameters, especially the deposition temperature was the key factor in forming the perovskite structure. The dielectric properties of the film deposited with optimized parameters were studied by an Agilent 4294A impedance analyzer at 1 MHz. The dielectric constant was 772, and the loss tangent was 0.006. In addition, the well-shaped hysteresis loop also showed that the film had a well performance in ferroelectric. The saturated polarization P, remnant polarization Pr and coercive field E were about 4.6 μC/cm2, 2.5 μC/cm2 and 23 kV/cm (the coercive voltage is 0.7 V), respectively. It is suggested the film should be a promising candidate for microwave applications and nonvolatile ferroelectric random access memories (NvFeRAMs). 相似文献
3.
用化学气相淀积生长方法,以乙烯为碳源、锗烷为锗源,在Si(100)衬底上外延生长出了C组分达3%的Ge1-xCx合金薄膜,研究表明随着生长温度和乙烯分压的提高均可导致Ge1-xCx薄膜中碳组分的增加;X射线衍射测量显示随着C组分的增加合金薄膜晶格常数不断减小,这表明外延薄膜中的C原子主要以替位式存在。红外吸收谱的测量结果显示Ge1-xCx合金的禁带宽度随着C组分的增加而线性增加,从0 67eV到0 87eV,与理论相符,说明碳的掺入有效地调节了禁带宽度。另外拉曼光谱显示Ge1-xCx合金在387cm-1出现一新峰,该峰是Ge1-xCx薄膜中的Ge在K点的双声子振动引起的。 相似文献
4.
Guo DongYun Li MeiYa Liu Jun Pei Ling Yu BenFang Zhao XingZhong Yang Bin Wang YunBo Yu Jun 《中国科学E辑(英文版)》2007,50(4):472-477
The Bi4Zr0.5Ti2.5O12 (BZT) thin films were fabricated on the LaNiO3 bottom electrode using sol-gel method. The structure and morphology of the films were characterized using X-ray diffraction, AFM and SEM. The results show that the films have a perovskite phase and dense microstructure. The 2Pr and 2Vc of the Pt/BZT/LaNiO3 capacitor are 28.2 μC/cm2 and 14.7 V respectively at an applied voltage of 25 V. After the switching of 1×1010 cycles, the Pr value decreases to 87% of its pre-fatigue values. The dielectric constant (ε) and the dissipation factor (tanδ) of the BZT thin films are about 204 and 0.029 at 1 kHz, respectively. The films show good insulating behavior according to the test of leakage current. The clockwise C-V hysteresis curve observed shows that the Pt/BZT/LaNiO3 structure has a memory effect because of the BZT film's ferroelectric polarization. 相似文献
5.
ZHENG Huajing ZHANG Jingquan FENG Lianghuan ZHENG Jiagui CAI Wei LI Bing CAI Yaping 《武汉理工大学学报(材料科学英文版)》2006,21(3):65-68
The structure and characteristics of CdTe thin filrns are closely dependent on the whole deposition process in close-space sublimation (CSS). The physical mechanism of CSS was analyzed aud the temperature distribution in CSS system was measured, and the influences of the increasing-temperature process and pressure on the preliminary nucleus creation were studied. The resuits indicate : tire samples deposited at different pressures hare a cubical structure of CdTe and the diffraction peaks of CdS and SnO2 : F. As the atmosphere pressure increases, the crystal size of CdTe decreases, the rate of the transparency of the thin film decreases and the absorption side moves towards the short-wave direction. After a 4-minute depositing process with a substrate teraw.rature of 500℃ and a source temperature of 620 ℃, the polycostallinc thin films can be mmade , so the production of high-quality integrated cell with StrO2: F/ CdS/ CdTe/ Au structure is hopeful. 相似文献
6.
Highly conductive IrO2 thin films were prepared on Si (100) substrates by means of pulsed laser deposition technique from an iridium metal target in an oxygen ambient atmosphere. Emphasis was put on the effect of oxygen pressure and substrate temperature on the structure, morphology and resistivity of IrO2 films. It was found that the above properties were strongly dependent on the oxygen pressure and substrate temperature. At 20 Pa oxygen ambient pressure, pure polycrystalline IrO2 thin films were obtained at substrate temperature in the 300-500℃ range with the preferential growth orientation of IrO2 films changed with the substrate temperature. IrO2 films exhibited a uniform and densely packed granular morphology with an average feature size increasing with the substrate temperature. The room-temperature resistivity variations of IrO2 films correlated well with the corresponding film morphology changes. IrO2 films with the minimum resistivity of (42 ±6)μΩ·cm was obtained at 500℃. 相似文献
7.
High refractive index TiO2 thin films were deposited on BK7 glass by reactive electron—beam (REB) evaporation at pressure of 2×10−2 Pa, deposition rate of 0.2 nm/s and at various substrate temperatures from 120°C to 300°C. The refractive index and the thickness
of the films were measured by visible spectroscopic ellipsometry (SE) and determined from transmission spectra. Optical properties
and structure features were characterized by UV-VIS, SEM and XRD, respectively. The measurement and analysis on transmission
spectra of all samples show that with the substrate temperature increasing from 120°C to 300°C, the refractive indices of
thin films increase from 1.7 to 2.1 and the films after heat treatment have higher refractive indices due to its crystallizing.
The XRD analysis results indicate that the structure of TiO2 thin films deposited on BK7 glass at substrate temperatures of 120°C, 200°C and 300°C is amorphous, after post-annealing
under air condition at 400°C for 1 hour, the amorphous structure is crystallized, the crystal phase is of 100% anatase with
strong preferred orientation (004) and the grain size of crystalline is within 3.6–8.1 nm, which is consistent with results
from SEM observation.
WANG Xue-hua: Born in 1976.
Funded by the Youth Project Foundation of Hubei Provincial Education Department (No. 2003B00) 相似文献
8.
Bi3.25La0.75Ti3O12(BLT) thin films were prepared on Pt/Ti/SiO2/Si substrate by the sol-gel method. The effect of annealing on their structures and ferroelectric properties was investigated.
The XRD patterns indicate that the BLT films annealed at different temperatures are randomly orientated and the single perovskite
phase is obtained at 550°C. The remnant polarization increases and the coercive field decreases with the annealing temperature
increasing. The leakage current density of the BLT films annealed at 700°C is about 5.8×10−8 Al cm2 at the electric field of 250 kV/cm.
Funded by the National Natural Science Foundation of China (No. 90407023) 相似文献
9.
Aluminium doped ZnO thin films(ZnO︰Al) were deposited on transparent polymer substrates at room temperature by rf magnetron sputtering method from a ZnO target with Al2O3 of 2.0 wt%. Argon gas pressure varied from 0.5 Pa to 2.5 Pa with radio frequency power of 120 W. XRD results showed that all the ZnO︰Al films had a polycrystalline hexagonal structure and a (002) preferred orientation with the c-axis perpendicular to the substrate. The grain sizes of the films were 6.3-14.8 nm.SEM images indicated the ZnO︰Al film with low Argon gas pressure was denser and the deposition rate of the films depended strongly on the Argon gas pressure, increasing firstly and then decreasing with increasing the pressure. The highest deposition rate was 5.2 nm/min at 1 Pa. The optical transmittance of the ZnO︰Al films increased and the blue shift of the absorption edge appeared when the Argon gas pressure increased. The highest transmittance of obtained ZnO︰Al films at 2.5 Pa was about 85% in the visible region. The electrical properties of the films were worsened with the increase of the Argon gas power from 1 Pa to 2.5 Pa. The resistivity of obtained film at 1.0 Pa was 2.79×10-2 Ω·cm. 相似文献
10.
(ZrO2)
x
(SiO2)1−x
(Zr-Si-O) films with different compositions were deposited on p-Si(100) substrates by using pulsed laser deposition technique.
X-ray photoelectron spectra (XPS) showed that these films remained amorphous after annealing at 800°C with RTA process in
N2 for 60 s. The XPS spectra indicated that Zr-Si-O films with x=0.5 suffered no obvious phase separation after annealing at 800°C, and no interface layer was formed between Zr-Si-O film
and Si substrate. While Zr-Si-O films with x >0.5 suffered phase separation to precipitate ZrO2 after annealing under the same condition, and SiO2 was formed at the interface. To get a good interface between Zr-Si-O films and Si substrate, Zr-Si-O films with bi-layer
structure (ZrO2)0.7(SiO2)0.3/(ZrO2)0.5(SiO2)0.5/Si was deposited. The electrical properties showed that the bi-layer Zr-Si-O film is of the lowest equivalent oxide thickness
and good interface with Si substrate.
Supported by the National Nature Science Foundation of China (Grant No. 60636010) and the National Basic Research Program
of China (“973” Program) (Grant No. 2004CB619004) 相似文献
11.
Uniform crystalline TiO2 thin films were coated on silica glass fibers by liquid phase deposition from aqueous solution of ammonium hexafluorotitanate at low temperature. TiO2 thin films and nanopowders were prepared by adding H3BO3 into (NH4)2TiF6 solution supersaturated with anatase nano-crystalline TiO2 at 40 ℃. The effects of the deposition conditions on the surface morphology, section morphology, thickness of the deposited TiO2 thin films were investigated. The results indicate that the growth rate and particle size of the thin films were controlled by both the deposition conditions and the amount of anatase nano-crystalline TiO2. 相似文献
12.
黄玲 《武汉理工大学学报(材料科学英文版)》2012,27(1):88-91
The PZT thin films were prepared on (111)- Pt/Ti/SiO2/Si substrates by sol-gel method, and lead acetate [Pb(CH3COO)2], zirconium nitrate [Zr(NO3)4] were used as raw materials. The X-ray diffractometer (XRD) and scanning electron microscopy (SEM) were used to characterize the phase structure and surface morphology of the films annealed at 650 ℃ but with different holding time. Ferroelectric and dielectric properties of the films were measured by the ferroelectric tester and the precision impedance analyzer, respectively. The PZT thin films were constructed with epoxy resin as a composite structure, and the damping properties of the composite were tested by dynamic mechanical analyzer (DMA). The results show that the films annealed for 90 minutes present a dense and compact crystal arrangement on the surface; moreover, the films also achieve their best electric quality. At the same time, the largest damping loss factor of the composite constructed with the 90 mins-annealed film shows peak value of 0.9, higher than the pure epoxy resin. 相似文献
13.
Lianshan Wang Xianglin Liu Yude Zan Du Wang Jun Wang Dacheng Lu Zhanguo Wang 《中国科学E辑(英文版)》1998,41(2):203-207
Single crystal GaN films of hexagonal modification have been fabricated on Al2O3/Si (001) substrates via a low pressure metalorganic chemical deposition (LP-MOCVD) method. the full width at half-maximum
of (0002) X-ray diffraction peak for the GaN film 1.1 μm thick was 72 arcmin, and the mosaic structure of the film was the
main cause of broadening to the X-ray diffraction peak. At room temperature, the photoluminescence (PL) spectrum of GaN exhibited
near band edge emission peaking at 365 nm.
Project supported by the “863” Advanced materials Committee of China and the Planning Commission of China. 相似文献
14.
Ag-TiO2 thin films were prepared on glasses.The morphology and structure of Ag-TiO2 films were investigated by XRD.SEM and FT-IR.The photocatalytic and hydrophilic properties of Ag-TiO2 thin films were also evaluated by examining photocatalytic degradation dichlorophos under sunlight illumination and the change of contact angle respectively.The research results show that the Ag-TiO2 thin film is mainly composed of 20-100nm Ag and TiO2 particles,The Ag-TiO2 thin films possess a super-hydrophilic ability and higher photocatalytic activity than that of pure TiO2 thin film. 相似文献
15.
The ignition-proof mechanism of ZM5 magnesium alloy added with 0.1% (mass fraction) rare earth (RE) was investigated. The oxide scales and substrates were characterized by scanning electronic microscope (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and tensile test. And an oxidation model of ZM5 alloy with RE was established. The results show that the ignition temperature of ZM5 alloy is particularly elevated from 654 to 823 ℃, the microstructure is refined, and the tensile strength i... 相似文献
16.
提出了一种测定工业废水中微量金铂钯的方法。方法利用脱氢双硫腙和双流腙硫上烷基加成产物(分别简称为TD—2和D—2)的氯仿溶液对微量金铂钯很强的选择萃取及富集能力,将这些金属离子从大量基体中分离富集,然后通过直流等离子体发射光谱法(DCP—AES)测定.详细研究了分离富集的条件以及基体元素对贵金属萃取的影响。 相似文献
17.
A new cyclometalated platinum complex containing 2, 5-bis(naphthalene-1-yl)-1,3,4-oxadiazole ligand was synthesized and characterized. The UV-Vis absorptions and photoluminescent properties of the ligand and its platinum complex were investigated A characteristic metal-ligand charge transfer absorption peak at 439 nm in the UV spectrum and a strong emission peak at 625 nm in the photoluminescence spectrum were observed for this complex in dichloromethane. Cyclic voltammtry (CV) analysis shows that the EHOMO (energy level of the highest occupied molecular orbital) and ELUMO (energy level of the lowest unoccupied molecular orbital) of the platinum complex are about -5.69 and -3.25 eV, respectively, indicating that the oxadiazole-based platinum complex has a potential application in electrophosphorescent devices used as a red-emitting material. 相似文献
18.
Local segregation in Cu-In precursors and its effects on the element distribution and microstructures of selenized CuInSe2 thin films were investigated. Cu-In precursors with an ideal total mole ratio of Cu to In of 0.92 were prepared by middle
frequency alternating current magnetron sputtering with Cu-In alloy target, then CuInSe2 absorbers for solar cells were formed by selenization process in selenium atmosphere. Scanning electron microscope and energy
dispersive X-ray spectroscope were used respectively to observe the surface morphologies and determine the compositions of
both Cu-In precursors and CuInSe2 thin films. Their microstructures were characterized by X-ray diffractometry and Raman spectroscope. The results show that
Cu-In precursors are mainly composed of Cu11In9 phase with In-rich solid solution. Stoichiometric CuInSe2 thin films with a homogeneous element distribution and single chalcopyrite phase can be synthesized from a segregated Cu-In
precursor film with an ideal total mole ratio of Cu to In of 0.92. CuInSe2 thin film shows P-type conductivity and its resistivity reaches 1.2×103 Θ·cm.
Foundation item: Project(2004AA513023) supported by the National High Technology Research and Development Program of China 相似文献
19.
The Bi3.25La0.75Ti3O12 thin films were fabricated on the Pt/Ti/SiO2/Si substrates using sol-gel method. The structure and morphology of the films were characterized using X-ray diffraction and atomic force microscopy. The thin films showed a perov- skite phase and dense microstructure. The 2Pr and 2Vc of the Bi3.25La0.75Ti3O12 thin films annealed at 700℃ were 18.6 μC/cm2 and 4.1 V, respectively, under an applied voltage 10 V. After the switching of 1×1010 cycles, the Pr value decreased to 90% of its pre-fatigue values. The films showed good insulating behavior according to the test of leakage current. The dielectric constant and the dissipation factor of the Bi3.25La0.75Ti3O12 thin films were about 176 and 0.046 at 1 kHz, respectively. 相似文献
20.
In this paper, uniform titania (TiO2) films have been formed at 50° on silanol SAMs by the liquid-phase deposition (LPD) method at a temperature below 100°C.
OTS (Octadecyltrichloro-Silane) self-assembled monolayers (SAMs) on glass wafers were used as substrates for the deposition
of titanium dioxide thin films. This functionalized organic surface has shown to be effective for promoting the growth of
films from titanic aqueous solutions by the LPD method at a low temperature below 100°C. The crystal phase composition, microstructure
and topography of the as-prepared films were characterized by various techniques, including X-ray diffraction (XRD), scanning
electron microscopy (SEM), and atomic force microscopy (AFM). The results indicate that the as-prepared thin films are purely
crystallized anatase TiO2 constituted by nanorods after being annealed at 500°. The pH values, concentration of reactants, and deposition temperatures
play important roles in the growth of TiO2 thin films.
Support by the National Natural Science Foundation of China (Grant No. 50672055) and National Key Technology R&D Program (Grant
No. 2006BAF02A28) 相似文献