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1.
Siti Nuurul Fatimah Hasim Muhammad Azmi Abdul Hamid Roslinda Shamsudin Azman Jalar 《Journal of Physics and Chemistry of Solids》2009,70(12):1501-1504
ZnO thin films have been successfully synthesized by thermal evaporation of pure zinc at 900 °C under the flow of different percentages of argon and oxygen gases. The films were characterized by X-ray diffraction (XRD), variable pressure scanning electron microscopy (VPSEM), energy dispersive X-ray spectroscopy (EDS) and UV–vis spectroscopy. The aim of this paper is to study the influence of the oxygen percentage on the structural and morphological properties of the ZnO films. VPSEM results show that very thick needle structures were produced at high oxygen percentages. EDS results revealed that only Zn and O are present in the sample, indicating a composition of pure ZnO. XRD results showed that the ZnO synthesized under different quantities of oxygen were crystalline with the hexagonal wurtzite structure. UV–vis spectroscopy results indicated that the optical band gap energies from the transmission spectrum are between 3.62 and 3.69 eV for ZnO thin films. 相似文献
2.
Thin films of SnSb2S4 have been prepared on glass substrate by using thermal evaporation techniques. The films were annealed in argon gas at low pressure in sealed glass ampoules at 85 °C, 150 °C, 275 °C and 325 °C. XRD of the films reveal that the low temperature annealed films are poly crystalline while the as deposited films and high annealed films are in amorphous states. There is no adequate variation in the photoconductivity response of the amorphous and crystalline phases. The transmittance of the films is low and having no transmittance below 740 nm. The band gap calculated by ellipsometry technique is in the range of 1.82–3.1 eV. The films have n-type conductivity but the film annealed at 325 °C show p-type conductivity. 相似文献
3.
Polycrystalline In2Se3 semiconducting thin films were prepared by using relatively simple chemical bath deposition method at room temperature by the reaction between indium chloride, tartaric acid, hydrazine hydrate and sodium selenosulphate in an aqueous alkaline medium. Various preparative conditions of thin film deposition are outlined. The as grown films were found to be transparent, uniform, well adherent and red in color. The films were characterized using X-ray diffraction (XRD), scanning electron microscopy, atomic absorption spectroscopy and energy dispersive atomic X-ray diffraction (EDAX). The XRD analysis of the film showed the presence of polycrystalline nature with hexagonal crystal structure. SEM study revels that the grains are homogenous, without cracks or pinholes and well covers the glass substrate. The optical absorption and electrical conductivity was measured. The direct optical band gap value for the films was found to be of the order of 2.35 eV at room temperature and have specific electrical conductivity of the order of 10−2 (Ω cm)−1 showing n-type conduction mechanism. The utility of the adapted technique is discussed from the view-point of applications considering the optoelectric and structural data. 相似文献
4.
P. Verardi F. Craciun N. Scarisoreanu G. Epurescu M. Dinescu I. Vrejoiu A. Dauscher 《Applied Physics A: Materials Science & Processing》2004,79(4-6):1283-1285
Thin films of Pb1-xLax(Zr0.65Ti0.35)1-x/4O3 with x=0.09 (PLZT 9/65/35) have been grown by pulsed laser deposition (PLD) and by PLD assisted by radio frequency (RF) discharge in oxygen which increases the plasma reactivity and reduces the oxygen vacancies in films and at the film-bottom electrode interface. Significant compositional, structural and dielectric differences have been found among samples grown in the same deposition conditions excepting for RF power. Films grown by RF-assisted PLD have less pyrochlore and are more oriented. For these films dielectric permittivity vs. temperature variation was typical of relaxor ferroelectrics and the temperature of the dielectric maximum was close to that obtained in bulk, but the permittivity value was much lower. This was attributed mainly to the influence of a low permittivity interface layer and to the detrimental effect of pyrochlore phase, still present in small quantities even in the films obtained by RF-PLD. The dielectric behavior of films grown without RF discharge was very different: no dielectric anomaly was observed, only a step increase above 180 °C. Moreover much higher dielectric loss was measured for these films. PACS 84.15.Fg; 77.84.-s; 77.22.Gm 相似文献
5.
L. Escobar-Alarcón D. A. Solís-Casados J. Perez-Alvarez S. Romero J. G. Morales-Mendez E. Haro-Poniatowski 《Applied Physics A: Materials Science & Processing》2014,117(1):31-35
The aim of this work was to report the application of an hybrid deposition configuration to deposit Titanium dioxide (TiO2) thin films modified with different amounts of bismuth (Bi:TiO2). The samples were synthesized combining a TiO2 laser ablation plasma with a flux of vapor of bismuth produced by thermal evaporation. By varying the deposition rate of Bi it was possible to control the amount of Bi incorporated in the film and consequently the film properties. A detailed compositional, structural, and optical characterization by XPS, RBS, Raman spectroscopy, and UV–Vis spectrometry techniques is discussed. Photocatalytic response of the deposited thin films was studied through the degradation of a malachite green solution. 相似文献
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7.
Tin oxide (SnO2) thin films were deposited by electrostatic spray deposition (ESD). The structural, optical and electrical properties of the films for different solvents were studied. The morphology of the deposited thin films was investigated by scanning electron microscopy. The optical transmission spectra of the films showed 66–75% transmittance in the visible region of spectrum. The electrical resistivity of thin films deposited using the different solvents ranged 1.08 × 10?3–1.34 × 10?3 Ω-cm. Overall, EG and PG were good solvents for depositing SnO2 thin films by the ESD technique with stable cone jet. 相似文献
8.
Jian Du Xin-liang Chen Cai-chi Liu Jian Ni Guo-fu Hou Ying Zhao Xiao-dan Zhang 《Applied Physics A: Materials Science & Processing》2014,117(2):815-822
Transparent conductive tin-doped indium oxide (In2O3:Sn, ITO) thin films with various Sn-doping concentrations have been prepared using the low cost reactive thermal evaporation (RTE) technique at a low growth temperature of ~160 °C. The structural characteristics, optical and electrical properties of the ITO thin films were investigated. These polycrystalline ITO films exhibited preferential orientation along (222) plane and possessed low resistivities ranging from 3.51 to 5.71 × 10?4 Ω cm. The decreased mobility was attributed to the scattering by ionized and neutral impurities at high doping concentrations. The optimized ITO thin film deposited with 6.0 wt% Sn-doping concentration exhibited a high average transparency of 87 % in the wavelength range of 380–900 nm and a low resistivity of 3.74 × 10?4 Ω cm with a high Hall mobility of 47 cm2 V?1s?1. A hydrogenated amorphous silicon and silicon–germanium (a-Si:H/a-SiGe:H) double-junction solar cell fabricated with the RTE-grown ITO electrodes presented a conversion efficiency of 10.51 %. 相似文献
9.
J.E. Williams R.P. Camata V.V. Fedorov S.B. Mirov 《Applied Physics A: Materials Science & Processing》2008,91(2):333-335
We have grown Cr doped ZnSe thin films by pulsed laser deposition on GaAs, sapphire and Si substrates through KrF excimer
laser ablation of hot-pressed targets containing appropriate stoichiometric mixtures of Zn, Se, and Cr species and hot-pressed
ceramic targets made of ZnSe and CrSe powders in vacuum and in an He background environment (10-4 Torr). Deposited films were analyzed using X-ray diffraction to determine crystallinity and energy dispersive X-ray fluorescence
to confirm Cr incorporation into the films. Photoluminescence measurements on the films show intracenter Cr2+ emission in the technologically important 2–2.6 μm spectral range.
PACS 78.66.hf; 78.66.-w; 78.55.-m; 78.66.Bz; 78.20.-e 相似文献
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11.
P.P. Hankare P.A. Chate I.S. Mulla 《Journal of Physics and Chemistry of Solids》2006,67(11):2310-2315
Zinc selenide (ZnSe) thin film have been deposited using chemical bath method on non-conducting glass substrate in a tartarate bath containing zinc sulfate, ammonia, hydrazine hydrate, sodium selenosulfate in an aqueous alkaline medium at 333 K. The deposition parameter of the ZnSe thin film is interpreted in the present investigation. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), optical absorption, electrical measurements, atomic absorption spectroscopy (AAS). The ZnSe thin layers grown with polycrystalline zinc blende system along with some amorphous phase present in ZnSe film. The direct optical band gap ‘Eg’ for the film was found to be 2.81 eV and electrical conductivity in the order of 10−8(Ω cm)−1 with n-type conduction mechanism. 相似文献
12.
《Current Applied Physics》2015,15(9):964-969
The effect of growth temperature on the phase evolution and morphology change of tin sulfide thin films by electron-beam evaporation was investigated. Orthorhombic tin monosulfide (SnS) was dominant at low growth temperature of 25 °C, whereas a sulfur-rich phase of Sn2S3 coalesced as the growth temperature increased over 200 °C. Thin film growth ceased at 280 °C due to re-evaporation of the tin sulfide. The dependence of growth temperature on the phase evolution of tin sulfide was confirmed by X-ray diffraction, scanning electron microscopy, and UV–Vis spectrophotometry. The lowest electrical resistivity of ∼51 Ω cm, with a majority hole concentration of ∼1017 cm−3, was obtained for the film grown at 100 °C, and the resistivity drastically increased with increasing growth temperature. This behavior was correlated with the emergence of resistive sulfur-rich Sn2S3 phase at high temperatures. 相似文献
13.
N. Koteeswara Reddy K. Ramesh R. Ganesan K.T. Ramakrishna Reddy K.R. Gunasekhar E.S.R. Gopal 《Applied Physics A: Materials Science & Processing》2006,83(1):133-138
Tin sulphide films were grown at different substrate temperatures by a thermal co-evaporation technique. The crystallinity of the films was evaluated from X-ray diffraction studies. Single-phase SnS films showed a strong (040) orientation with an orthorhombic crystal structure and a grain size of 0.12 μm. The films showed an electrical resistivity of 6.1 Ω cm with an activation energy of 0.26 eV. These films exhibited an optical band gap of 1.37 eV and had a high optical absorption coefficient (>104 cm-1) above the band-gap energy. The results obtained were analysed to evaluate the potentiality of the co-evaporated SnS films as an absorber layer in solar photovoltaic devices. PACS 78.40.Fy; 68.60.-p; 61.10.Nz; 68.55.-a; 78.66.-w 相似文献
14.
Thermal evaporated thin Sn?O films subjected to annealing treatments in air in the range 473–1173 K and in Ar in the range 473–773 K followed by annealings in air up to 1373 K were studied by CEMS (Conversion Electron Mössbauer Spectroscopy). Complementary Mössbauer and X-ray measurements were also performed on SnO powder that underwent the same series of annealings. The presence of the intermediate oxide Sn3O4 was detected. A temptative hyperfine characterization for the Sn2+ site in Sn3O4 is given. 相似文献
15.
以M oS2粉末为原料,以氩气为携载气体,在400~600℃温度范围内利用热蒸发方法在硅衬底表面制备了不同厚度的M oS2薄膜.利用X射线衍射和扫描电子显微镜分析了M oS2薄膜的结构和表面形貌,发现M oS2薄膜由多晶M oS2粒子组成,颗粒均匀,平均纳米颗粒尺寸约为60 nm .利用紫外可见光光谱仪测量了其吸收特性,发现样品在720 nm附近有很强的吸收.应用霍尔效应和伏安法研究了M oS2/Si样品的接触特性和电子的运输特性,发现该异质结具有良好的整流特性,即正向电压下电流随电压呈指数增长,而在反向偏压下漏电流很小,电子迁移率可达到6.730×102 cm2/(V · s).实验结果表明MoS2薄膜具有良好的电学特性,可用来制备晶体管和集成电路等器件. 相似文献
16.
ZnSe thin films have been prepared by inert gas condensation method at different gas pressures. The influence of deposition pressure, on structural, optical and electrical properties of polycrystalline ZnSe films have been investigated using X-ray diffraction (XRD), optical transmission and conductivity measurements. The X-ray diffraction study reveals the sphalerite cubic structure of the ZnSe films oriented along the (1 1 1) direction. The structural parameters such as particle size [6.65-22.24 nm], strain [4.01-46.6×10−3 lin−2 m−4] and dislocation density [4.762-18.57×1015 lin m−2] have been evaluated. Optical transmittance measurements indicate the existence of direct allowed optical transition with a corresponding energy gap in the range 2.60-3.00 eV. The dark conductivity (σd) and photoconductivity (σph) measurements, in the temperature range 253-358 K, indicate that the conduction in these materials is through an activated process having two activation energies. σd and σph values decrease with the decrease in the crystallite size. The values of carrier life time have been calculated and are found to decrease with the reduction in the particle size. The conduction mechanism in present samples has been explained, and the density of surface states [9.84-21.4×1013 cm−2] and impurity concentration [4.66-31.80×1019 cm−3] have also been calculated. 相似文献
17.
We present an experimental study on the electrochromic properties of MoO3, WO3 and mixed WO3-MoO3 thin films prepared by thermal evaporation. We have constructed symmetric and quasi-symmetric electrochromic cells incorporating
the evaporated oxide films as electrochromic layers. Li+ doped V2O5 films served as ion storage layers. The symmetric cells were found to exhibit significantly improved optical properties compared
to the quasi-symmetric ones, with very low luminous transmittance values in the colored state, which makes them suitable for
large-area window applications.
Paper presented at the 5th Euroconference on Solid State Ionics, Benalmádena, Spain, Sept. 13–20, 1998. 相似文献
18.
In this paper, the experimental results regarding some structural, electrical and optical properties of ZnO thin films prepared by thermal oxidation of metallic Zn thin films are presented.Zn thin films (d=200–400 nm) were deposited by thermal evaporation under vacuum, onto unheated glass substrates, using the quasi-closed volume technique. In order to obtain ZnO films, zinc-coated glass substrates were isochronally heated in air in the 300–660 K temperature range, for thermal oxidation.X-ray diffraction (XRD) studies revealed that the ZnO films obtained present a randomly oriented hexagonal nanocrystalline structure. Depending on the heating temperature of the Zn films, the optical transmittance of the ZnO films in the visible wavelength range varied from 85% to 95%. The optical band gap of the ZnO films was found to be about 3.2 eV. By in situ studying of the temperature dependence of the electrical conductivity during the oxidation process, the value of about 2×10−2 Ω−1 m−1 was found for the conductivity of completely oxidized ZnO films. 相似文献
19.
Michal Novotn?? P??emysl Fitl Anna Krasilnikova Sytchkova Ji???- Bul?-?? Jan Lanaok Petr Pokorna David Najdek Jia Boan 《Central European Journal of Physics》2009,7(2):327-331
The effect of pulsed laser treatment of metal, and metal blacks, was studied. Gold and black gold thin films were fabricated
by thermal evaporation of gold in a vacuum and nitrogen atmosphere respectively. Black gold films were grown in a nitrogen
atmosphere at pressures of 200 Pa and 300 Pa. UV pulsed laser radiation (λ = 266 nm, τ = 4 ns), with fluence ranging from 1 mJ·cm−2 to 250 mJ·cm−2 was used for the film treatment in a vacuum and nitrogen atmosphere. The nitrogen pressure was varied up to 100 kPa. Surface
structure modifications were analyzed by optical microscopy, atomic force microscopy (AFM) and scanning electron microscopy
(SEM). Energy dispersive X-ray spectroscopy (EDX) was used for chemical characterization of the samples. A significant dependence
of the film optical and structural properties on laser treatment conditions (laser fluence, ambient pressure and number of
applied pulses) was found. The threshold for observable damage and initiation of changes of morphology for gold and black
gold surfaces was determined. Distinct modifications were observed for fluences greater than 106 mJ·cm−2 and 3.5 mJ·cm−2 for the gold and black gold films respectively. Absorbtivity of the black gold film is found to decrease with an increase
in the number of laser pulses. Microstructural and nanostructural modifications after laser treatment of the black gold film
were observed. EDX analysis revealed that no impurities were introduced into the samples during both the deposition and laser
treatment.
相似文献
20.
R. Cristescu T. Kocourek L. Stamatin M. Jelinek I.N. Mihailescu 《Applied Surface Science》2006,252(13):4652-4655
We report the first successful deposition of type II cryoglobulin blood protein thin films by matrix assisted pulsed laser evaporation (MAPLE) using a KrF* excimer laser source (λ = 248 nm, τFWHM ≈ 20 ns) operated at a repetition rate of 10 Hz. We demonstrate by AFM and FTIR that MAPLE-deposited thin films consist of starting type II cryoglobulin only, maintaining its chemical structure and biological functionality, being properly collected and processed. The dependence on incident laser fluence of the induced surface morphology is presented. The presence of type II cryoglobulin was revealed as aggregates of globular material in the MAPLE-deposited thin films and confirmed by standard cryoglobulin tests. 相似文献