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Films of different thickness (50, 100, 150 and 200 nm) were deposited by thermal evaporation in vacuum on two types of substrates glass and ITO. The deposition was performed under a pressure of 10−6 mB with a rate of 0.25 nm/s. Films surface investigations showed morphological and structural changes in function of films thickness and the nature of the substrate. Films optical transmission was analysed in the 280-1600 nm spectral range and the electrical measurements were done in low vacuum (10−1:10−2 mB) and in dark. 相似文献
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D. Paul Joseph 《Thin solid films》2009,517(21):6129-6867
Studies on spray deposited transparent conducting Li doped SnO2 thin films are scarce. Li (0 to 5 wt.%) doped SnO2 thin films spray deposited onto glass substrates at 773 K in air from chloride precursors were studied for their structural, optical and temperature dependent electrical behaviors. X-ray diffraction patterns indicated single phase with polycrystalline nature. Systematic variation in surface morphology on Li doping was examined by scanning electron microscopy and atomic force microscopy. Film thickness, optical band gap (direct and indirect), sheet resistance and figure of merit were computed from spectral transmittance and temperature dependent resistivity data. Lithium doping was found to decrease the value of sheet resistance by an order in magnitude. Activation energy was computed from temperature dependent electrical resistivity data measured in the range 300 to 448 K. The 4 wt.% Li doped SnO2 film was found to have a high value of figure of merit among other films. The results are discussed. 相似文献
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《Vacuum》1999,52(1-2):45-49
Undoped and doped (indium and aluminium) zinc oxide (ZnO) thin films have been prepared by spray pyrolysis, and the effect of the doping and annealing atmosphere on the electrical, optical and structural properties of the produced films has been investigated. The deposited films have a high resistivity. Annealing the films in an argon atmosphere or under vacuum leads to a substantial reduction of the electrical resistivity of the films and to an increase on the degree of cristallinity of the deposited material. The most pronounced changes were observed in the films annealed in Argon. The results also indicate that doping highly influences the electrical and structural properties of the films, which is more pronounced in the films doped with Indium. 相似文献
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Meherun Nesa Mehnaz Sharmin Khandker S. Hossain A. H. Bhuiyan 《Journal of Materials Science: Materials in Electronics》2017,28(17):12523-12534
Nanostructured spray deposited zinc (Zn) doped copper oxide (CuO) thin films were characterized by employing X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), atomic force microscopy (AFM) and ultraviolet–visible–near infrared (UV–Vis–NIR) spectroscopy. XRD patterns of CuO and Zn doped CuO thin films indicated monoclinic structure with the preferred orientation along \(\left( {\bar 111} \right)\) plane. Maximum value of crystallite size is found about 28.24 nm for 5 at% Zn doped CuO thin film. In FESEM images, nanoparticles were observed around the nucleation center. EDX analysis confirms the presence of all component elements in CuO and Zn doped CuO thin films. Analysis by AFM of CuO and Zn doped CuO thin films figured out decrease of surface roughness due to Zn doping. UV–Vis–NIR spectroscopy showed that CuO and Zn doped CuO thin films are highly transparent in the NIR region. Optical band gap of CuO thin films decreased with substrate temperature and that of Zn doped CuO thin films increased with Zn concentration. Refractive index of CuO and Zn doped CuO thin films raised with photon wavelength and became constant in the NIR region. 5 at% Zn doped CuO thin film showed the highest optical conductivity and the lowest electrical resistivity at room temperature. 相似文献
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ZnS films were deposited by spray pyrolysis on glass at 500 °C substrate temperature. In order to study the influence of fluorine on the properties of ZnS film, undoped and F-doped films were investigated using X-ray diffraction, scanning electron microscopy and optical transmittance spectroscopy. The absorption coefficient was measured and correlated with the photon energy to estimate the energy gap, which rises from 3.20 to 3.35 eV with increased F content. Carrier concentrations of our samples were determined from Hall effect measurements. It was found that the carrier concentration increases from 7.0 × 1012 cm− 3 to 8.0 × 1013 cm− 3 with increasing F content from 0 to 6 wt.% in ZnS films. 相似文献
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P. V. Bhuvaneswari K. Ramamurthi R. Ramesh Babu 《Journal of Materials Science: Materials in Electronics》2018,29(20):17201-17208
Copper bismuth sulfide thin films were deposited at 200 °C, 300 °C, 400 °C and 500 °C on the glass substrates by electron beam evaporation method. X-ray diffraction study revealed that the copper bismuth sulfide films of single and mixed phases were formed as a function of substrate temperatures. Substrate temperature of 300 °C and 400 °C formed single phase Cu4Bi4S9 and Cu4Bi5S10 films respectively whereas substrate temperature of 500 °C formed mixed phases of Cu4Bi4S9 and Cu4Bi5S10 film. Crystallite size, dislocation density and microstrain of the films were modified by the various substrate temperatures. Surface morphology of the film Cu4Bi5S10 deposited at 400 °C examined by scanning electron microscopy showed the distribution of spherical shaped particles on the film surface. The presence of copper, bismuth and sulfur elements in the deposited films was confirmed using energy dispersive spectral studies. The calculated direct optical band gap energy of the films deposited at different substrate temperature varied from 1.47 to 1.64 eV and the absorption coefficient is in the order of 106 cm?1. 相似文献
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Thin films of lead oxide were synthesized by cost effective spray pyrolysis technique at different substrate temperatures on glass substrates. Effect of substrate temperature on the growth mechanism and physical properties of the films was investigated. All the films were polycrystalline in nature with tetragonal structure corresponding to α-PbO. The films coated at 225 °C and 275 °C were (1 0 1) oriented, while the films deposited at 325 °C and 375 °C were (0 0 2) oriented. Above 375 °C, the pure tetragonal nature deteriorated and the peaks corresponding to orthorhombic phase were observed. The band gap value was found to be in the range of 2.3 to 2.62 eV. All the films had a resistivity of the order of 103 ohm-cm. A minimum resistivity of 0.0191 × 103 ohm-cm was obtained for the film coated at 325 °C. The activation energy increased with increase in substrate temperature. 相似文献
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Polycrystalline lead iodide (PbI2) thin films have been deposited by spray pyrolysis method using N,N-dimethylformamide (DMF) as solvent as a function of several deposition parameters. DMF is used as an alternative to water due to the larger solubility limit of PbI2 in this solvent. In this work, the solution rate during the deposition time of 3 h was varied in the range of 0.11 cm3/min up to 0.30 cm3/min. A growth rate varying from 19 Å s?1 up to 47 Å s?1 was obtained as a function of solution rate. Dark current as a function of temperature for the final films reveals that for larger solution rates smaller values of electrical resistivity is obtained. For a solution rate of 0.30 cm3/min, an electrical transport activation energy (E a) of about 0.65 eV was measured for the whole temperature range. On the other hand, for the sample deposited with a solution rate of 0.11 cm3/min, two main transport mechanisms can be observed with an activation energy of about 1.23 eV for temperatures above 50 °C. The effect of substrate temperature is also discussed. Samples were deposited in the temperature range of 170 °C up to 250 °C with a fixed solution rate of 0.16 cm3/min. In addition, the films were exposed to X-ray irradiation in the mammography diagnosis region, using a molybdenum (Mo) anode and a peak tube potential between 26 and 36 kV (equivalent photon energies between 10 keV and 15 keV). 相似文献
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Undoped and Ga doped ZnO thin films (1% GZO, 3% GZO and 5% GZO) were grown on c-Al2O3 substrates using the 1, 3 and 5 at. wt.% Ga doped ZnO targets by pulsed laser deposition. X-ray diffraction studies revealed that highly c-axis oriented, single phase, undoped and Ga doped ZnO thin films with wurtzite structure were deposited. Micro-Raman scattering analysis showed that Ga doping introduces defects in the host lattice. The E2High mode of ZnO in Ga doped ZnO thin film was observed to shift to higher wavenumber indicating the presence of residual compressive stress. Appearance of the normally Raman inactive B1 modes (B1Low, 2B1Low and B1High) due to breaking of local translational symmetry, also indicated that defects were introduced into the host lattice due to Ga incorporation. Band gap of the Ga doped ZnO thin films was observed to shift to higher energy with the increase in doping concentration and is explicated by the Burstein-Moss effect. Electrical resistivity measurements of the undoped and GZO thin films in the temperature range 50 to 300 K revealed the metal to semiconductor transition for 3 and 5% GZO thin films. 相似文献
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Influence of Al concentration on structural and optical properties of Al-doped ZnO thin films 总被引:1,自引:0,他引:1
Deniz Kadir Takci Ebru Senadim Tuzemen Kamuran Kara Sadi Yilmaz Ramazan Esen Ozge Baglayan 《Journal of Materials Science: Materials in Electronics》2014,25(5):2078-2085
Undoped ZnO and Al-doped zinc oxide (ZnO:Al) thin films with different Al concentrations were prepared onto Si (100) substrate by pulsed filtered cathodic vacuum arc deposition system at room temperature. The influence of doping on the structural and optical properties of thin films was investigated. The preferential (002) orientation was weakened by high aluminum doping in films. Raman measurement was performed for the doping effects in the ZnO. Atomic force microscopy images revealed that the surface of undoped ZnO film grown at RT was smoother than that of the Al-doped ZnO (ZnO:Al) films. The reflectance of all films was studied as a function of wavelength using UV–Vis–NIR spectrophotometer. Average total reflectance values of about 35 % in the wavelength range of 400–800 nm were obtained. Optical band gap of the films was determined using the reflectance spectra by means of Kubelka–Munk formula. From optical properties, the band gap energy was estimated for all films. 相似文献
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Vinoth Kumar Jayaraman Arturo Maldonado Álvarez Monserrat Bizarro María de la Luz Olvera Amador 《Journal of Materials Science: Materials in Electronics》2018,29(18):15321-15328
Aluminium and indium co-doped zinc oxide (AIZO) thin films were deposited using ultrasonic spray pyrolysis. Depositions were performed by varying the acetic acid and water content in the spraying solution which resulted in the formation of different nanostructures like hexagons, flowers, chisels, curved nanostructures, hexagonal pyramids, super grown hexagons, and inter-connected nanostructures. Further, the physical properties such as structural, optical, electrical, and surface texture parameters were examined. The structural studies showed that films were of crystalline nature, with different crystallite sizes and grown with a preferential orientation along (002) plane. The optical transmittance assessments proved that films were highly transparent (>?80%) in the visible region. The electrical sheet resistance was found to be in the range 29–1K Ω/□. Surface parameters like average roughness, root mean square roughness, and peak-valley height values helped to understand the homogeneity of the thin films. Finally, the suitability of AIZO films for transparent conductive oxide applications were tested by estimating the figure of merit (FOM). Among the different solution conditions, films fabricated using a starting solution containing 25 ml of acetic acid and 25 ml of water exhibited the lowest resistivity (2.47?±?0.03?×?10?3 Ω-cm) along with the highest FOM (5.83?±?0.42?×?10?3/Ω). 相似文献
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Data are presented on the structure and photoelectric properties of lead sulfide films chemically deposited from aqueous solutions
containing ammonium halides. The concentration of ammonium halides in the solution has a crucial effect on the microstructure
and texture of the films. The photosensitivity and spectral response of the films are shown to correlate with their microstructure. 相似文献
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N.J. Podraza D.B. Saint JohnS.W. Ko H.M. SchulzeJ. Li E.C. Dickey S. Trolier-McKinstry 《Thin solid films》2011,519(9):2919-2923
Nickel manganite thin films of interest for microbolometer applications have been prepared using chemical solution and spin spray deposition and studied using transmission electron microscopy to quantify the material crystallinity and spectroscopic ellipsometry to extract the complex dielectric function (ε = ε1 + iε2) and film microstructure. A parameterization for ε over a spectral range from 0.04 to 5.15 eV has been developed to model well-crystallized nickel manganite, and the visible-range critical point features, infrared vibrations, and optical absorption onset have been identified. A multiple sample analysis structural model and procedure has been developed for spin spray deposited films exhibiting complicated void evolutions with thickness. Variations in ε and crystallite grain size have been observed as a function of film processing and indicate that the optical properties and microstructural information gained from spectroscopic ellipsometry is useful in process monitoring for this material system. 相似文献
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CuInS2 is a promising chalcopyrite semiconducting material for solar cell fabrication. Using aqueous solutions of cupric chloride,
indium trichloride and thiourea, we deposited thin CuInS2 films on glass at 350°C and studied their structural, optical and electrical properties. From the XRD pattern the chalcopyrite
structure of these films was confirmed. The films were polycrystalline. The grain size estimated from scanning electron micrographs
was found to be of the order of 1μm. Resistivity of the film was measured for temperatures ranging from 77 to 473 K. Band
gap values were determined from optical transmission data. Hall mobility and carrier concentration at room temperature were
calculated using Van der Pauw-Hall method. 相似文献