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1.
Bao Y. Man Hong Z. Xi Chuan S. Chen Mei Liu Jing Wei 《Central European Journal of Physics》2008,6(3):643-647
Using a pulsed laser deposition (PLD) process on a ZnO target in an oxygen atmosphere, thin films of this material have been
deposited on Si(111) substrates. An Nd: YAG pulsed laser with a wavelength of 1064 nm was used as the laser source. The influences
of the deposition temperature, laser energy, annealing temperature and focus lens position on the crystallinity of ZnO films
were analyzed by X-ray diffraction. The results show that the ZnO thin films obtained at the deposition temperature of 400°C
and the laser energy of 250 mJ have the best crystalline quality in our experimental conditions. The ZnO thin films fabricated
at substrate temperature 400°C were annealed at the temperatures from 400°C to 800°C in an atmosphere of N2. The results show that crystalline quality has been improved by annealing, the optimum temperature being 600°C. The position
of the focusing lens has a strong influence on pulsed laser deposition of the ZnO thin films and the optimum position is 59.5
cm from the target surface for optics with a focal length of 70 cm.
相似文献
2.
R.A. Gunasekaran J.D. Pedarnig M. Dinescu 《Applied Physics A: Materials Science & Processing》1999,69(6):621-624
A parametric study of the growth of La0.5Sr0.5CoO3 (LSCO) thin films on (100) MgO substrates by pulsed-laser deposition (PLD) is reported. Films are grown under a wide range
of substrate temperature (450–800 °C), oxygen pressure (0.1–0.9 mbar), and incident laser fluence (0.8–2.6 J/cm2). The optimum ranges of temperature, oxygen pressure, and laser fluence to produce c-axis oriented films with smooth surface morphology and high metallic conductivity are identified. Films deposited at low
temperature (500 °C) and post-annealed in situ at higher temperatures (600–800 °C) are also investigated with respect to their
structure, surface morphology, and electrical conductivity.
Received: 20 November 1998 / Accepted: 6 July 1999 / Published online: 21 October 1999 相似文献
3.
I. Fasaki M. Kandyla M. Kompitsas 《Applied Physics A: Materials Science & Processing》2012,107(4):899-904
Nanocomposite thin films formed by gold nanoparticles embedded in a nickel oxide matrix have been synthesized by a new variation of the pulsed laser deposition technique. Two actively synchronized laser sources, a KrF excimer laser at 248 nm and an Nd:YAG laser at 355 nm, were used for the simultaneous ablation of nickel and gold targets in oxygen ambient. The structural, morphological, and electrical properties of the obtained nanocomposite films were investigated in relation to the fluence of the laser irradiating the gold target. The nanocomposite thin films were tested as electrochemical hydrogen sensors. It was found that the addition of the gold nanoparticles increased the sensor sensitivity significantly. 相似文献
4.
Deuk-Hee Lee Kyoungwon Kim Yoon Soo Chun Sangsig Kim Sang Yeol Lee 《Current Applied Physics》2012,12(6):1586-1590
High quality transparent conductive gallium-doped zinc oxide (GZO) thin films were deposited on glass substrates using rf-magnetron sputtering system at the temperature ranging from room temperature (RT) to 500 °C. The temperature-dependence of Ga doping effect on the structural, optical and electrical properties in ZnO has been investigated. For the GZO thin films deposited at over 200 °C, (103) orientation was strongly observed by X-ray diffraction analysis, which is attributed to the substitution of Ga elements into Zn site. X-ray photoelectron spectroscopy measurements have confirmed that oxygen vacancies were generated at the temperature higher than 300 °C. This might be due to the effective substitution of Ga3+ for Zn site at higher temperature. It was also found that the optical band gap increases with deposition temperature. The optical transmittance of GZO thin films was above 87% in the visible region. The GZO thin films grown at 500 °C showed a low electrical resistivity of 4.50 × 10?4 Ω cm, a carrier concentration of 6.38 × 1020 cm?3 and a carrier mobility of 21.69 cm2/V. 相似文献
5.
M. F. Al-Kuhaili S. M. A. Durrani I. A. Bakhtiari 《Applied Physics A: Materials Science & Processing》2010,98(3):609-615
Thin films of molybdenum oxide were deposited in vacuum by pulsed laser ablation using a xenon fluoride (351 nm) and a krypton
fluoride (248 nm) excimer lasers. The films were deposited on unheated substrates and were post-annealed in air in the temperature
range 300–500°C. The structural, morphological, chemical, and optical properties of the films were studied. As-deposited films
were found to be dark. The transparency of the films was improved with annealing in air. The films were polycrystalline with
diffraction peaks that belong to the orthorhombic phase of MoO3. The surface morphology of the films showed a layered structure. Both the grain size and surface roughness increased with
annealing temperature. The stoichiometry of the films improved upon annealing in air, with the best stoichiometry of MoO2.95 obtained for films deposited by the XeF laser and annealed at 400°C. Similarly, the best transparency, with a transmittance
exceeding 80%, was obtained with the films annealed in the temperature range 400–450°C. 相似文献
6.
Hopp B. Smausz T. Kresz N. Nagy P.M. Juhász A. Ignácz F. Márton Z. 《Applied Physics A: Materials Science & Processing》2003,76(5):731-735
Allergic-type diseases are current nowadays, and they are frequently caused by certain metals. We demonstrated that the metal
objects can be covered by Teflon protective thin layers using a pulsed laser deposition procedure. An ArF excimer laser beam
was focused onto the surface of pressed PTFE powder pellets; the applied fluences were 7.5–7.7 J/cm2. Teflon films were deposited on fourteen-carat gold, silver and titanium plates. The number of ablating pulses was 10000.
Post-annealing of the films was carried out in atmospheric air at oven temperatures between 320 and 500 °C. The thickness
of the thin layers was around 5 μm. The prepared films were granular without heat treatment or after annealing at a temperature
below 340 °C. At 360 °C a crystalline, contiguous, smooth, very compact and pinhole-free thin layer was produced; a melted
and re-solidified morphology was observed above 420 °C. The adhesion strength between the Teflon films and the metal substrates
was determined. This could exceed 1–4 MPa depending on the treatment temperature. It was proved that the prepared Teflon layers
can be suitable for prevention of contact between the human body and allergen metals and so for avoidance of metal allergy.
Received: 12 June 2002 / Accepted: 13 June 2002 / Published online: 4 November 2002
RID="*"
ID="*"Corresponding author. E-mail: bhopp@physx.u-szeged.hu 相似文献
7.
Chan y Díaz E. Duarte-Moller A. Camacho Juan M. Castro-Rodríguez R. 《Applied Physics A: Materials Science & Processing》2012,106(3):619-624
SnO2 thin films have been deposited on glass substrates by pulsed Nd:YAG laser at different oxygen pressures, and the effects
of oxygen pressure on the physical properties of SnO2 films have been investigated. The films were deposited at substrate temperature of 500°C in oxygen partial pressure between
5.0 and 125 mTorr. The thin films deposited between 5.0 to 50 mTorr showed evidence of diffraction peaks, but increasing the
oxygen pressure up to 100 mTorr, three diffraction peaks (110), (101) and (211) were observed containing the SnO2 tetragonal structure. The electrical resistivity was very sensitive to the oxygen pressure. At 100 mTorr the films showed
electrical resistivity of 4×10−2 Ω cm, free carrier density of 1.03×1019 cm−3, mobility of 10.26 cm2 V−1 s−1 with average visible transmittance of ∼87%, and optical band gap of 3.6 eV. 相似文献
8.
Y. W. Li Z. G. Hu F. Y. Yue W. Z. Zhou P. X. Yang J. H. Chu 《Applied Physics A: Materials Science & Processing》2009,95(3):721-725
(La0.5Sr0.5)CoO3 (LSCO) thin films have been fabricated on silicon substrate by the pulsed laser deposition method. The effects of substrate
temperature and post-annealing condition on the structural and electrical properties are investigated. The samples grown above
650°C are fully crystalline with perovskite structure. The film deposited at 700°C has columnar growth with electrical resistivity
of about 1.99×10−3 Ω cm. The amorphous films grown at 500°C were post-annealed at different conditions. The sample post-annealed at 700°C and
10−4 Pa has similar microstructure with the sample in situ grown at 700°C and 25 Pa. However, the electrical resistivity of the
post-annealed sample is one magnitude higher than that of the in situ grown sample because of the effect of oxygen vacancy.
The temperature dependence of resistivity exhibits semiconductor-like character. It was found that post-annealing by rapid
thermal process will result in film cracks due to the thermal stress. The results are referential for the applications of
LSCO in microelectronic devices. 相似文献
9.
K.?Sudheendran M.?Ghanashyam?Krishna K.?C.?James?Raju 《Applied Physics A: Materials Science & Processing》2009,95(2):485-492
Bismuth Zinc niobate (Bi1.5Zn1.0Nb1.5O7) thin films were deposited by pulsed laser deposition (PLD) method on fused silica substrates at different oxygen pressures.
The structural, microwave dielectric and optical properties of these thin films were systematically studied for both the as-deposited
and the annealed films at 600°C. The as-deposited films were all amorphous in nature but crystallized on annealing at 600°C
in air. The surface morphology as studied by atomic force microscopy (AFM) reveals ultra-fine grains in the case of as-deposited
thin films and cluster grain morphology on annealing. The as-deposited films exhibit refractive index in the range of 2.36–2.53
(at a wavelength of 750 nm) with an optical absorption edge value of 3.30–3.52 eV and a maximum dielectric constant of 11
at 12.15 GHz. On annealing the films at 600°C they crystallize to the cubic pyrochlore structure accompanied by an increase
in band gap, refractive index and microwave dielectric constant. 相似文献
10.
Rakesh Malik S. Annapoorni S. Lamba S. Mahmood R. S. Rawat 《Applied Physics A: Materials Science & Processing》2011,105(1):233-238
Nickel ferrite thin films were deposited by a pulsed laser deposition (PLD) technique on silicon substrate at room temperature
in a vacuum of 5×10−5 mbar. The films were subjected to different annealing temperatures from 300–900°C and were also exposed to single shot energetic
hydrogen ions using a Dense Plasma Focus (DPF) device. The changes induced in the films exposed at different distances from
the top of the anode were investigated. The structural, morphological and magnetic properties of the annealed and exposed
samples were investigated. X-ray diffraction (XRD) studies reveal the presence of a single phase of nickel ferrite after annealing.
SEM micrographs indicate an increase in the grain size, both on annealing as well as on exposure to hydrogen ions. Annealing
and hydrogen ion irradiation induced an enhancement in the magnetic moments. Laser droplets which are inherent in films deposited
by laser ablation were found to be dispersed as a result of single shot hydrogen ion irradiation from the DPF. 相似文献
11.
W. Deng T. Ohgi H. Nejo D. Fujita 《Applied Physics A: Materials Science & Processing》2001,72(5):595-601
Highly conductive and transparent indium tin oxide (ITO) thin films, each with a thickness of 100 nm, were deposited on glass
and Si(100) by direct current (DC) magnetron sputtering under an argon (Ar) atmosphere using an ITO target composed of 95%
indium oxide and 5% tin oxide for photon-STM use. X-ray diffraction, STM observations, resistivity and transmission measurements
were carried out to study the formation of the films at substrate temperatures between 40 and 400 °C and the effects of thermal
annealing in air between 200 and 400 °C for between1 and 5 h. The film properties were highly dependent on deposition conditions
and on post-deposition film treatment. The films deposited under an Ar atmosphere pressure of ∼1.7×10-3 Torr by DC power sputtering (100 W) at substrate temperatures between 40 and 400 °C exhibited resistivities in the range
3.0–5.7×10-5 Ω m and transmissions in the range 71–79%. After deposition and annealing in air at 300 °C for 1 h, the films showed resistivities
in the range 2.9–4.0×10-5 Ω m and transmissions in the range 78–81%. Resistivity and transmission measurements showed that in order to improve conductive
and transparent properties, 2 h annealing in air at 300 °C was necessary. X-ray diffraction data supported the experimental
measurements of resistivity and transmission on the studies of annealing time. The surface roughness and film uniformity improve
with increasing substrate temperature. STM observations found the ITO films deposited at a substrate temperature of 325 °C,
and up to 400 °C, had domains with crystalline structures. After deposition and annealing in air at 300 °C for 1 h the films
still exhibited similar domains. However, after deposition at substrate temperatures from 40 °C to 300 °C, and annealing in
air at 300 °C for 1 h, the films were shown to be amorphous. More importantly, the STM studies found that the ITO film surfaces
were most likely to break after deposition at a substrate temperature of 325 °C and annealing in air at 300 °C for 2 or 3 h.
Such findings give some inspiration to us in interpreting the effects of annealing on the improvement of conductive and transparent
properties and on the transition of phases. In addition, correlations between the conductive/transparent properties and the
phase transition, the annealing time and the phase transition, and the conductive/transparent properties and the annealing
time have been investigated.
Received: 10 July 2000 / Accepted: 27 October 2000 / Published online: 9 February 2001 相似文献
12.
Dong Zhang Changzheng Wang Yunlong Liu Qiang Shi Wenjun Wang 《Optics & Laser Technology》2012,44(4):1136-1140
Thin films of zinc oxide were grown on glass substrates by thermal oxidation. The metallic zinc films were thermally oxidized at different temperatures ranging from 300 to 600 °C to yield ZnO thin films. The structural property of the thin films was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The X-ray diffraction measurements showed that the films oxidized at 300 °C were not oxidized entirely, and the films deposited at 600 °C had better crystalline quality than the rest. When the oxidation temperature increased above 400 °C, the films exhibited preferred orientation along (002) and high transmittance ranging from 85% to 98% in vis–near-infrared band. Meanwhile, the films showed a UV emission at about 377 nm and green emission. With the increasing of oxidation temperature, the intensity of green emission peak was enhanced, and then decreased, disappearing at 600 °C, and the case of UV emission increased. Furthermore, a strong green emission was observed in the film sintered in pure oxygen atmosphere. 相似文献
13.
Md Alauddin Jae Kyu Song Seung Min Park 《Applied Physics A: Materials Science & Processing》2010,101(4):707-711
Aluminum-doped zinc oxide (AZO) thin films have been deposited on amorphous fused silica substrates by pulsed laser ablation
of a Zn:Al metallic targets. We varied the film growth condition such as the substrate temperature and Al concentrations.
The films were deposited at substrate temperatures ranging from 20 to 600°C with oxygen partial pressure of 1 torr. The characteristics
of the deposited films were examined by analyzing their photoluminescence (PL), X-ray diffraction (XRD), and UV–visible spectra.
It is observed that the optical bandgap energy of the deposited films increased with the increase of Al concentration and
substrate temperature. Besides, the PL peak energy shifted to blue and the Stokes shift became larger as the Al content increased. 相似文献
14.
C. Grivas D.S. Gill S. Mailis L. Boutsikaris N.A. Vainos 《Applied Physics A: Materials Science & Processing》1998,66(2):201-204
2 O3) thin films on glass substrates is performed by pulsed laser ablation of a metallic indium target in an oxygen atmosphere.
X-ray diffraction analysis verifies that a transition, from amorphous to polycrystalline film growth, occurs at a temperature
of 150 °C. Films grown under optimized conditions exhibit optical transmission higher than 80% in the visible light. Ultraviolet
radiation (λ= 325 nm) induced dynamic holographic recording in films deposited at specific temperature and oxygen pressure
settings is also demonstrated.
Received: 25 April 1997/Accepted: 27 May 1997 相似文献
15.
Production and characterization of Nd,Cr:GSGG thin films on Si(001) grown by pulsed laser ablation 总被引:2,自引:0,他引:2
P.R. Willmott P. Manoravi K. Holliday 《Applied Physics A: Materials Science & Processing》2000,70(4):425-429
Nd,Cr:Gd3Sc2Ga3O12 (GSGG) thin films have been produced for the first time. They were grown on Si(001) substrates at 650 °C by pulsed laser
ablation at 248 nm of a crystalline Nd,Cr:GSGG target rod. The laser plume was analyzed using time-of-flight quadrupole mass
spectroscopy, and consisted of elemental and metal oxide fragments with kinetic energies typically in the range 10 to 40 eV,
though extending up to 100 eV. Although films deposited in vacuum using laser fluences of 0.8±0.1 J cm−2 reproduced the Nd,Cr:GSGG bulk stoichiometry, those deposited using fluences above ≈3 J cm−2 resulted in noncongruent material transfer and were deficient in Ga and Cr. Attempts to grow films using synchronized oxygen
or oxygen/argon pulses yielded mixed oxide phases. Under optimal growth conditions, the films were heteroepitaxial, with GSGG(001)[100]∥Si(001)[100],
and exhibited Volmer–Weber-type growth. Room-temperature emission spectra of the films suggest efficient non-radiative energy
transfer between Cr3+ and Nd3+ ions, similar to that of the bulk crystal.
Received: 1 October 1999 / Accepted: 15 October 1999 / Published online: 23 February 2000 相似文献
16.
We report thin tantalum pentoxide (Ta2O5) films grown on quartz and silicon substrates by the pulsed laser deposition (PLD) technique employing a Nd:YAG laser (wavelength 5=532 nm) in various O2 gas environments. The effect of oxygen pressure, substrate temperature, and annealing under UV irradiation using a 172-nm excimer lamp on the properties of the grown films has been studied. The optical properties determined by UV spectrophotometry were also found to be a sensitive function of oxygen pressure in the chamber. At an O2 pressure of 0.2 mbar and deposition temperatures between 400 and 500 °C, the refractive index of the films was around 2.18 which is very close to the bulk Ta2O5 value of 2.2, and an optical transmittance around 90% in the visible region of the spectrum was obtained. X-ray diffraction measurements showed that the as-deposited films were amorphous at temperatures below 500 °C and possessed an orthorhombic (#-Ta2O5) crystal structure at temperatures above 600 °C. The most significant result of the present study was that oxygen pressure could be used to control the composition and modulate optical band gap of the films. It was also found that UV annealing can significantly improve the optical and electrical properties of the films deposited at low oxygen pressures (<0.1 mbar). 相似文献
17.
M. C. Kao H. Z. Chen S. L. Young 《Applied Physics A: Materials Science & Processing》2010,98(3):595-599
The preferred (002) orientation zinc oxide (ZnO) nanocrystalline thin films have been deposited on FTO-coated glass substrates
by sol–gel spin-coating technology and rapid thermal annealing for use in dye-sensitized solar cells (DSSC). The effects of
preannealing temperature (100 and 300°C) on the microstructure, morphology and optical properties of ZnO thin films were studied.
The ZnO thin films were characterized by X-ray diffraction (XRD), scanning electron microscopic (SEM) and Brunauer–Emmett–Teller
(BET) analysis. The photoelectric performance of DSSC was studied by I–V curve and the incident photon-to-current conversion efficiency (IPCE), respectively. From the results, the intensities of
(002) peaks of ZnO thin films increases with increasing preannealing temperature from 100°C to 300°C. The increase in pore
size and surface area of ZnO films crystallized at the increased preannealing temperature contributed to the improvement on
the absorption of N3 dye onto the films, the short-circuit photocurrent (J
sc) and open-circuit voltage (V
oc) of DSSC. The higher efficiency (η) of 2.5% with J
sc and V
oc of 8.2 mA/cm2 and 0.64 V, respectively, was obtained by the ZnO film preannealed at 300°C. 相似文献
18.
E. Fazio S. Patanè S. Scibilia A.M. Mezzasalma G. Mondio F. Neri S. Trusso 《Current Applied Physics》2013,13(4):710-716
Nanocrystalline ZnO thin films were grown by means of pulsed laser deposition. The ablation process was carried out at relatively low background oxygen gas pressure (10 Pa) and by varying the substrate temperature up to 600 °C. Information on the structural and morphological properties of the deposited thin films have been obtained by means of X-ray photoelectron, Raman spectroscopies, X-ray diffraction (XRD) and atomic force microscopy (AFM). The results showed that all the deposited films are sub-stoichiometric in oxygen and with a hexagonal wurtzite crystalline structure, characterized by features of some tens of nanometers in size. An improvement of the films' crystalline quality was observed for the deposition temperature of 300 °C while the further increase of the deposition temperature up to 600 °C induces a worsening of the material's structural properties with the development of a large amount of nanoparticle's clusters. The analysis of the XRD patterns shows a growth crystallographic preferential direction as a function of the deposition temperature, in agreement with the appearance of the only E2 optical phonon mode in the Raman spectra. Such findings are compatible with the changes observed in the photoluminescent (PL) optical response and was related to the modification of the ZnO thin film structural quality. 相似文献
19.
Thin films of aluminium-doped zinc oxide (AZO) and indium tin oxide (ITO) were deposited on glass substrates by laser ablation in an oxygen environment. The electrical and optical properties of films grown at various oxygen pressures were compared. With no substrate heating, highly transparent and conducting films were obtained with oxygen pressures between 15 and 23 mTorr for both materials. We obtained a specific resistivity of 1.8᎒-3 Q cm for AZO and 1.1᎒-3 Q cm for ITO. By heating the substrate to 160 °C or 200 °C, the resistivity was further reduced to 1.1᎒-3 Q cm for AZO and 3.9᎒-4 Q cm for ITO. The average transmission of visible light (450-750 nm) was between 82% and 98% in most cases. The results suggest that AZO is a promising alternative to ITO. 相似文献
20.
N. Sankara Subramanian B. Santhi T. Sornakumar G. Karthik Subbaraj C. Vinoth G. Murugan 《Ionics》2004,10(3-4):273-282
Undoped and antimony doped tin oxide thin films of different thicknesses were prepared on mineral glass substrate by spray
pyrolysis method via sol-gel route. Both the films show good transmittance in the visible region. Band gap energy of both
films lies between 3 to 3.5 eV. X-ray diffraction studies of undoped and antimony doped tin oxide thin films for various annealing
temperature show polycrystalline tetragonal structure of SnO2 with preferred orientation of (110) and (101), respectively and from the XRD data, grain size were also evaluated. AFM images
of Undoped and antimony doped tin oxide thin films annealed at 375 °C depict the film thickness and indicate uniform surface
pattern without dark pits and with strains of some ups exceeding the specified limit. The prepared films were tested in a
specially developed test rig for Liquefied Petroleum Gas detection at different operating temperatures. The response characteristics
of the films for LPG detection show maximum sensitivity and minimum response time at the operating temperature 400 °C. Studies
indicate that antimony doped tin oxide thin film are one among the suitable candidates for LPG detection with a detection
sensitivity and response time (t90) of 11 and 140 seconds, respectively.
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003. 相似文献