共查询到20条相似文献,搜索用时 15 毫秒
1.
L.P. Peng L. Fang X.F. Yang H.B. Ruan Y.J. Li Q.L. Huang C.Y. Kong 《Physica E: Low-dimensional Systems and Nanostructures》2009,41(10):1819-1823
In-doped ZnO (ZnO:In) transparent conductive thin films were deposited on glass substrates by RF magnetron sputtering. The effect of substrate temperature on the structural, electrical and optical properties of the ZnO:In thin films was investigated. It was found that higher temperature improves the crystallinity of the films and promotes In substitution easily. ZnO:In thin films with the best crystal quality were fabricated at 300 °C, which exhibit a larger grain size of 29 nm and small tensile strain of 0.9%. The transmittance of all the films was revealed to be over 85% in the visible range independence of the substrate temperatures and the lowest resistivity of ZnO:In thin films is 2.4×10−3 Ω cm. 相似文献
2.
《Physica E: Low-dimensional Systems and Nanostructures》2010,42(10):1819-1823
In-doped ZnO (ZnO:In) transparent conductive thin films were deposited on glass substrates by RF magnetron sputtering. The effect of substrate temperature on the structural, electrical and optical properties of the ZnO:In thin films was investigated. It was found that higher temperature improves the crystallinity of the films and promotes In substitution easily. ZnO:In thin films with the best crystal quality were fabricated at 300 °C, which exhibit a larger grain size of 29 nm and small tensile strain of 0.9%. The transmittance of all the films was revealed to be over 85% in the visible range independence of the substrate temperatures and the lowest resistivity of ZnO:In thin films is 2.4×10−3 Ω cm. 相似文献
3.
This paper describes the effect of doping on the composition, surface morphology and optical, structural and electrical properties of Al doped ZnO thin films by pulsed laser deposition. SEM analysis shows that the crystalline nature of the deposited films decreases with an increase of Al doping concentration from 1% to 6%. In the AFM analysis, the surface roughness of the deposited films increases by increasing the doping concentration of Al. Al doping strongly influences the optical properties of the ZnO thin films. Optical transmittance spectra show a very good transmittance in the visible region (450–700 nm). The calculated optical band gap was found to be in the range from 3.405 to 3.464 eV. Structural analysis confirms that the increases of Al concentration decrease the crystallinity of the ZnO films and the particle size decreases from 45.7±0.09 to 28.0±0.02 nm. In the Raman analysis, the active mode of Al(=1%) doped ZnO films were observed at 434.81 cm−1. The shifts of the active mode (E2) show the presence of tensile stress in the deposited films. The electrical properties of the deposited films showed that the values of the Hall mobility was in the range between 2.51 and 10.64 cm2/V s and the carrier concentration between 15.7 and 0.78×1017 and the resistivity values between 1.59 and 10.97 Ωcm, depending on the doping concentration. 相似文献
4.
Because of having similarities in many physical as well as chemical properties to those of Zn, Cu has been strategically used as an effective dopant e.g., Al, Ga, F, etc., to change the optical, electrical and the micro-structural properties of ZnO thin films for obtaining its favorable opto-electronic performance as a transparent conducting oxide suitable for devices. Present study demonstrates the growth of transparent conducting ZnO:Ga:Cu thin films, by low power RF magnetron sputtering at a low substrate temperature (100 °C). Highly crystalline ZnO:Ga:Cu film with preferred c-axis orientation has been obtained demonstrating a high magnitude of transmission ~85% in the visible range and a high electrical conductivity ~40 S cm–1, facilitated by large crystallite size (~29 nm), introducing reduced grain boundary scattering. XPS O 1S spectrum reveals the presence of a significant fraction of oxygen atoms effectively increasing the optical transparency. Incorporation of Ga and Cu ions into the ZnO matrix promotes violation of the local translational symmetry as suggested by the relaxation of Raman selection rules for the network, evident by the presence of strong (B1high–B1low) modes which are typically Raman inactive. The consequences of Cu doping has been compared with identically prepared ZnO and ZnO:Ga films. 相似文献
5.
Properties of reactively sputtered W–B–N thin film as a diffusion barrier for Cu metallization on Si
L. C. Leu D. P. Norton L. McElwee-White T. J. Anderson 《Applied Physics A: Materials Science & Processing》2009,94(3):691-695
Thin films of W–B–N (10 nm) have been evaluated as diffusion barriers for Cu interconnects. The amorphous W–B–N thin films
were prepared at room temperature via reactive magnetron sputtering using a W2B target at various N2/(Ar + N2) flow ratios. Cu diffusion tests were performed after in-situ deposition of 200 nm Cu. Thermal annealing of the barrier stacks
was carried out in vacuum at elevated temperatures for one hour. X-ray diffraction patterns, sheet resistance measurement,
cross-section transmission electron microscopy images, and energy-dispersive spectrometer scans on the samples annealed at
500°C revealed no Cu diffusion through the barrier. The results indicate that amorphous W–B–N is a promising low resistivity
diffusion barrier material for copper interconnects. 相似文献
6.
Microstructure and optical properties of nanocrystalline ZnO and ZnO:(Li or Al) thin films 总被引:1,自引:0,他引:1
Zinc oxide thin films (ZnO, ZnO:Li, ZnO:Al) were deposited on glass substrates by a sol-gel technique. Zinc acetate, lithium acetate, and aluminum chloride were used as metal ion sources in the precursor solutions. XRD analysis revealed that Li doped and undoped ZnO films formed single phase zincite structure in contrast to Al:ZnO films which did not fully crystallize at the annealing temperature of 550 °C. Crystallized films had a grain size under 50 nm and showed c-axis grain orientation. All films had a very smooth surface with RMS surface roughness values between 0.23 and 0.35 nm. Surface roughness and optical band tail values increased by Al doping. Compared to undoped ZnO films, Li doping slightly increased the optical band gap of the films. 相似文献
7.
Determination of the optimal parameters for the fabrication of ZnO thin films prepared by spray pyrolysis method 总被引:1,自引:0,他引:1
In this work, ZnO thin films have been prepared by spray pyrolysis deposition method on the glass substrates. The effect of
deposition parameters, such as deposition rate, substrate temperature and solution volume has been studied by X-ray diffraction
(XRD) method, UV–Vis–NIR spectroscopy, scanning electron microscopy (SEM), and electrical measurements. The XRD patterns indicate
polycrystalline wurtzite structure with preferred direction along (0 0 2) planes. Thin films have transparency around 90%
in the visible range. The optical band gap was determined at 3.27 eV which did not change significantly. Evolution of electrical
results containing the carriers’ density, sheet resistance and resistivity are in agreement with structural results. All the
results suggest the best deposition parameters are: deposition rate, R = 3 ml/min, substrate temperature, T
s = 450°C and thickness of the thin films t = 110–130 nm. 相似文献
8.
Parshina L. S. Novodvorsky O. A. Panchenko V. Ya. Khramova O. D. Cherebilo Ye. A. Lotin A. A. Wenzel C. Trumpaicka N. Bartha J. W. 《Laser Physics》2011,21(4):790-795
The production of n- and p-type high-quality film structures is a foreground task in tackling the problem of growing the light-emitting p-n junctions based on zinc oxide. The ZnO:N and ZnO:P thin-film samples are produced from ceramic targets using the pulsed laser
deposition. Zn3N2, MgO, and Zn3P2 are introduced in the ZnO ceramic targets for the fabrication of the p-type ZnO films. Gases O2 and N2O are used as buffer gases. The thermal annealing of the ZnO films is employed. The resistance and photoluminescence (PL)
spectra of the ZnO films are measured prior to and after annealing. The dependence of the ZnO PL peak amplitude and position
prior to and after annealing on the level of doping with nitrogen and phosphorus is established. The PL characteristics of
the films are studied at cw optical excitation using a He-Cd laser with a radiation wavelength of 325 nm. The PL spectra in
the interval 300–700 nm are recorded by an HR4000 Ocean Optics spectrometer in the temperature range 10–400 K. The effect
of the conditions for the film deposition on the PL spectra is analyzed. The effect of the N- and P-doping level of the ZnO
films on the PL intensity of the films and the position of the PL bands in the UV region is investigated. The short-wavelength
(250–400 nm) transmission spectra of the ZnO:P films are measured. The effect of the P-doping level on the band gap of the
ZnO films is studied. 相似文献
9.
Fanhao Zeng Xiang Xiong Baiyun Huang 《Applied Physics A: Materials Science & Processing》2010,99(2):459-463
High-quality Co(Cr)(50–66 nm)/Ti(Cr)(25–30 nm)/ZnO(165–225 nm) films were grown on Si substrates by the pulsed-laser deposition
technique at 450–500°C. The microstructure of the films and their magnetic properties were investigated by X-ray diffraction,
transmission electron microscopy and a vibrating sample magnetometer. It was found that the Co(Cr)/Ti(Cr)/ZnO thin films had
a highly preferential c-axis direction normal to the surface of the substrate, and the ZnO sublayer had columnar structures in the growth direction.
The interface of the multi-layer films is smooth without interface reaction. The as-produced films had in-plane easy magnetization.
It indicates that the enhancements of the magnetic properties of the films are mainly ascribed to the grain structure and
multi-domain state of the Co-alloy layer, which can be controlled by the ZnO sublayer. 相似文献
10.
A wet chemical deposition method for preparing transparent conductive thin films on the base of Al-doped ZnO (AZO) nanoparticles
has been demonstrated. AZO nanoparticles with a size of 7 nm have been synthesised by a simple precipitation method in refluxed
conditions in ethanol using zinc acetate and Al-isopropylate. The presence of Al in ZnO was revealed by the EDX elemental
analysis (1.8 at.%) and UV–Vis spectroscopy (a blue shift due to Burstein–Moss effect). The obtained colloid solution with
the AZO nanoparticles was used for preparing by spin-coating thin films on glass substrates. The film demonstrated excellent
homogeneity and transparency (T > 90%) in the visible spectrum after heating at 400 °C. Its resistivity turned to be excessively high (ρ = 2.6 Ω cm) that
we ascribe to a poor charge percolation due to a high film porosity revealed by SEM observations. To improve the percolation
via reducing the porosity, a sol–gel solution was deposited “layer-by-layer” in alternation with layers derived from the AZO
colloid followed by heating. As it was shown by optical spectroscopy measurements, the density of thus prepared film was increased
more than twice leading to a significant decrease in resistivity to 1.3 × 10−2 Ω cm. 相似文献
11.
The resistivity of transparent conducting Al‐ and Ga‐doped ZnO (AZO and GZO) thin films prepared with a thickness in the range from 20 to 200 nm on glass substrates at a temperature below 200 °C was found to increase with exposure time when tested in a high humidity environment (air at 90% relative humidity and 60 °C). The resistivity stability (resistivity increase) was considerably affected by the thin film thickness. In particular, thin films with a thickness below about 50 nm were very unstable. The increase in resistivity is interpreted as carrier transport being dominated by grain boundary scattering resulting from the trapping of free electrons due to oxygen adsorption on the grain boundary surface. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
12.
Mg-doped ZnO nanoparticles were synthesized by a simple chemical method at low temperature with Mg:Zn atomic ratio from 0
to 7%. The synthesis process is based on the hydrolysis of zinc acetate dihydrate and magnesium acetate tetrahydrate were
heated under refluxing at 65 °C using methanol as a solvent. X-ray diffraction analysis reveals that the Mg-doped ZnO crystallizes
in a wurtzite structure with crystal size of 5–12 nm. These nanocrystals self-aggregated themselves into hollow spheres of
size of 800–1100 nm. High resolution transmission electron microscopy images show that each sphere is made up of numerous
nanoparticles of average diameter 5–11 nm. The XRD patterns, SEM and TEM micrographs of doping of Mg in ZnO confirmed the
formation of hollow spheres indicating that the Mg2+ is successfully substituted into the ZnO host structure of the Zn2+ site. Furthermore, the UV–Vis spectra and photoluminescence (PL) spectra of the ZnO nanoparticles were also investigated.
The band gap of the nanoparticles can be tuned in the range of 3.36–3.55 eV by the use of the dopants. 相似文献
13.
Kuo-Sheng Kao Shang-Hao Chang Po-Tsung Hsieh Chih-Ming Wang Da-Long Cheng 《Applied Physics A: Materials Science & Processing》2009,96(2):529-533
Three-layered ZnO/Ag–Ti/ZnO structures were prepared using both the sol-gel technique and DC magnetron sputtering. This study
focuses on the electrical and optical properties of the ZnO/Ag–Ti/ZnO multilayers with various thicknesses of the Ag–Ti layer.
The ZnO thin film prepared by the sol–gel method was dried at 300°C for 3 minutes, and a fixed thickness of 20 nm was obtained.
The thickness of the Ag–Ti thin film was controlled by varying the sputtering time. The Ag–Ti layer substantially reduced
the electrical resistivity of the sol–gel-sprayed ZnO thin films. The sheet resistance of the Ag–Ti layer decreased dramatically
and then became steady beyond a sputtering time of 60 s. The sputtering time of Ag–Ti thin film deposition was determined
to be 60 s, taking into account the optical transmittance. Consequently, the transmittance of the ZnO/Ag–Ti/ZnO multilayer
films was 71% at 550 nm and 60% at 350 nm. The sheet resistance was 4.2 Ω/sq. 相似文献
14.
为适应宽光谱高效率硅基薄膜太阳电池的应用需求,本文尝试采用直流磁控溅射技术在553 K衬底温度下生长氢化Mg和Ga共掺杂ZnO(HMGZO)透明导电氧化物(TCO)薄膜.通过对薄膜微观结构、表面形貌、电学以及光学性能的测试和分析,详细地研究了氢气(H2)流量(0—16.0 sccm)对HMGZO薄膜结晶特性及光电性能的影响.实验结果表明:生长获得的HMGZO薄膜均为六角纤锌矿结构的多晶薄膜,择优取向为(002)晶面生长方向.薄膜的生长速率随着氢气流量的增加呈现逐渐减小趋势,主要归因于溅射产额的减小.适当的氢气引入会引起晶粒尺寸的增加.随着氢气流量由0增加至4.0 sccm,ZnO薄膜电阻率从177?·cm急剧减小至7.2×10-3?·cm,主要是由于H施主的引入显著地增加了载流子浓度;然而进一步增加氢气流量(4.0—16.0 sccm)造成电阻率的轻微增加,主要归因于载流子浓度的减小以及过多氢杂质引入造成杂质散射的增加.所有生长获得的HMGZO薄膜平均光学透过率在波长λ~320—1100 nm范围内可达87%以上.由于Mg的作用及Burstein-Moss效应的影响造成了带隙展宽,带隙变化范围~3.49—3.70 eV,其中最大光学带隙Eg可达~3.70 eV. 相似文献
15.
《Current Applied Physics》2014,14(6):862-867
Transparent conductive zinc oxide (ZnO) thin films were synthesized by a sol–gel spin coating method with the addition of Ga(NO3)3 in a Zn(CH3COO)2 solution and exposed to electron beam treatment. The UV–Vis spectra demonstrated that all of the films had transmittances of over 85% in the visible region. When Ga(NO3)3 was added to the ZnO precursor solution, the resistivity of the ZnO thin film decreased and the carrier concentration increased significantly. After electron beam treatment was performed on the 0.4 at.% Ga-doped ZnO film, the optical band gap increased and the resistivity significantly decreased resulting from the increases of the carrier concentration and mobility. By combining Ga doping and electron beam treatment, the resistivity of the ZnO thin film was reduced by a factor of nine hundred. 相似文献
16.
ZnO thin films were grown on (111) CaF2 substrates by magnetron sputtering at room temperature. Structural and optical properties of the ZnO thin films were studied. XRD analysis showed that the ZnO thin films had the (002) preferential orientation. The transmittance of ZnO thin films was over 80% in the visible range. The optical band gap of the ZnO thin films was 3.26 eV. The optical constants (n,k) of the ZnO thin films in the wavelength range 300–1000 nm were obtained by infrared spectroscopic ellipsometry measurement. PL spectra of ZnO thin films showed strong UV near-band-edge emission peak at 376.5 nm and weak visible red emission at 643.49 nm using He–Cd laser as the light source, using a synchrotron radiation light source PL spectra showed three emission peak at 320 nm, 410 nm and 542 nm respectively. 相似文献
17.
F. Kadi Allah S. Yapi Abé C.M. Núñez L. Cattin A. Bougrine F.R. Díaz 《Applied Surface Science》2007,253(23):9241-9247
Al or Sn doped ZnO films were deposited by spray pyrolysis using aqueous solutions. The films were deposited on either indium tin oxide coated or bare glass substrates. ZnCl2, AlCl3 and SnCl2 were used as precursors. The effect of ZnCl2 molar concentration (0.1-0.3 M) and doping percentage (2-4% AlCl3 or SnCl2) have been investigated. The main goal of this work being to grow porous ZnO thin films, small temperature substrates (200-300 °C) have been used during the spray pyrolysis deposition. It is shown that, if the X-ray diffraction patterns correspond to ZnO, the films deposited onto bare glass substrate are only partly crystallized while those deposited onto ITO coated glass substrate exhibit better crystallization. The homogeneity of the films decreases when the molar concentration of the precursor increases, while the grain size and the porosity decrease when the Al doping increases. The optical study shows that band tails are present in the absorption spectrum of the films deposited onto bare glass substrate, which is typical of disordered materials. Even after annealing 4 h at 400 °C, the longitudinal resistivity of the films is quite high. This result is attributed to the grain boundary effect and the porosity of the films. Effectively, the presence of an important reflection in the IR region in samples annealed testifies of a high free-carriers density in the ZnO crystallites. Finally it is shown that when deposited in the same electrochemical conditions, the transmission of a polymer film onto the rough sprayed ZnO is smaller than that onto smooth sputtered ZnO. 相似文献
18.
Takashi Ogi Ferry Iskandar Yoshifumi Itoh Kikuo Okuyama 《Journal of nanoparticle research》2006,8(3-4):343-350
In2O3:Sn (Indium Tin Oxide; ITO) films were prepared from a sol solution with highly crystalline ITO nanoparticles (less than 20 nm in size with 10 at.% Sn) which had been prepared by low-pressure spray pyrolysis (LPSP) in a single step. The ITO sol solution was prepared by dispersing LPSP-prepared ITO nanoparticles into ultra pure water. The nanoparticle ITO film was deposited on a glass substrate using a dip-coating method and then annealed in air at various temperatures. The optical transmittances of the ITO films were measured by UV–Vis spectrometry, and the films were found to have a high transparency to visible light (in the case of a film thickness of 250 nm annealed at 400°C, the transparency was in excess of 95% over the range λ=450–800 nm, with a maximum value near 100% at wavelengths above λ=700 nm). The optical transmittances of the films were influenced by the size of the ITO particle used, the film thickness and the annealing temperature. The ITO films showed a minimum resistivity of 9.5×10−2 Ω cm, and their resistivity was affected by both the ITO particle size and the annealing temperature used. 相似文献
19.
Fabrication and properties of ZnO:Cu and ZnO:Ag thin films 总被引:1,自引:0,他引:1
V.S. Khomchenko T.G. Kryshtab A.K. Savin L.V. Zavyalova N.N. Roshchina V.E. Rodionov O.S. Lytvyn V.I. Kushnirenko V.B. Khachatryan J.A. Andraca-Adame 《Superlattices and Microstructures》2007,42(1-6):94
Thin films of ZnS and ZnO:Cu were grown by an original metal–organic chemical vapour deposition (MOCVD) method under atmospheric pressure onto glass substrates. Pulse photo-assisted rapid thermal annealing of ZnO:Cu films in ambient air and at the temperature of 700–800 C was used instead of the common long-duration annealing in a vacuum furnace. ZnO:Ag thin films were prepared by oxidation and Ag doping of ZnS films. At first a closed space sublimation technique was used for Ag doping of ZnO films. The oxidation and Ag doping were carried out by a new non-vacuum method at a temperature >500 C. Crystal quality and optical properties were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), and photoluminescence (PL). It was found that the doped films have a higher degree of crystallinity than undoped films. The spectra of as-deposited ZnO:Cu films contained the bands typical for copper, i.e. the green band and the yellow band. After pulse annealing at high temperature the 410 and 435 nm photoluminescent peaks were observed. This allows changing of the emission colour from blue to white. Flat-top ZnO:Ag films were obtained with the surface roughness of 7 nm. These samples show a strong ultraviolet (UV) emission at room temperature. The 385 nm photoluminescent peak obtained is assigned to the exciton–exciton emission. 相似文献
20.
Effects of deposition temperature on the structural and morphological properties of thin ZnO films fabricated by pulsed laser deposition 总被引:3,自引:0,他引:3
Rakhi Khandelwal Amit Pratap Singh Avinashi Kapoor Sorin Grigorescu Paola Miglietta Nadya Evgenieva Stankova Alessio Perrone 《Optics & Laser Technology》2008,40(2):247-251
ZnO thin films were grown on Si(1 0 0) substrates using pulsed laser deposition in O2 gas ambient (10 Pa) and at different substrate temperatures (25, 150, 300 and 400 °C). The influence of the substrate temperature on the structural and morphological properties of the films was investigated using XRD, AFM and SEM. At substrate temperature of T=150 °C, a good quality ZnO film was fabricated that exhibits an average grain size of 15.1 nm with an average RMS roughness of 3.4 nm. The refractive index and the thickness of the thin films determined by the ellipsometry data are also presented and discussed. 相似文献