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1.
Zinc nitride thin films were deposited by magnetron sputtering using ZnN target in plasma containing either N2 or Ar gases. The rf-power was 100 W and the pressure was 5 mTorr. The properties of the films were examined with thermal treatments up to 550 °C in N2 and O2 environments. Films deposited in Ar plasma were opaque and conductive (ρ ∼ 10− 1 to 10− 2 Ω cm, ND ∼ 1018 to 1020 cm− 3) due to excess of Zn in the structure. After annealing at 400 °C, the films became more stoichiometric, Zn3N2, and transparent, but further annealing up to 550 °C deteriorated the electrical properties. Films deposited in N2 plasma were transparent but very resistive even after annealing. Both types of films were converted into p-type ZnO upon oxidation at 400 °C. All thermally treated zinc nitride films exhibited a shoulder in transmittance at around 345 nm which was more profound for the Ar-deposited films and particularly for the oxidized films. Zinc nitride has been found to be a wide band gap material which makes it a potential candidate for transparent optoelectronic devices. 相似文献
2.
Thick aluminum-doped zinc oxide films were deposited at substrate temperatures from 100 °C to room temperature on polyethylene terephthalate by radio frequency magnetron sputtering, varying the deposition parameters such as radio frequency power and working pressure.Structural, optical and electrical properties were analyzed using an x-ray diffractometer, a spectrophotometer and a four-point probe, respectively. Films were polycrystalline showing a strong preferred c-axis orientation (002). The best optical and electrical results were achieved using a substrate temperature of 100 °C. Furthermore, high transmittances close to 80% in the visible wavelength range were obtained for those films deposited at the lowest Argon pressure used of 0.2 Pa. In addition, resistivities as low as 1.1 × 10− 3 Ω cm were reached deposited at a RF power of 75 W. Finally, a comparison of the properties of the films deposited on polymer and glass substrates was performed, obtaining values of the figure of merit for the films on polymer comparable to those obtained on glass substrates, 17,700 Ω− 1 cm− 1 vs 14,900 Ω− 1 cm− 1, respectively. 相似文献
3.
S.R. NalageM.A. Chougule Shashwati SenP.B. Joshi V.B. Patil 《Thin solid films》2012,520(15):4835-4840
Sol-gel method has been employed for the synthesis of nanocrystalline nickel oxide (NiO). The NiO powders were sintered at 400-700 °C for 1 h in an air. Thin films of sintered powders were prepared on glass substrate using spin coating technique and changes in the structural, morphological, electrical and optical properties were studied. The structural and microstructural properties of nickel oxide films were studied by means of X-ray diffraction and field emission scanning electron microscopy. Structural analysis shows that all the films are crystallized in the cubic phase and present a random orientation. Surface morphology of the nickel oxide film consists of nanocrystalline grains with uniform coverage of the substrate surface with randomly oriented morphology. The electrical conductivity showed the semiconducting nature with room temperature electrical conductivity increased from 10− 4 to 10− 2 (Ω cm) − 1 after sintering. The electron carrier concentration (n) and mobility (μ) of NiO films annealed at 400-700 °C were estimated to be of the order of 1.30 to 3.75 × 1019 cm− 3 and 1.98 to 4.20 × 10− 5 cm2 V− 1 s− 1.The decrease in the band gap energy from 3.86 to 3.47 eV was observed for NiO sintered between 400 and 700 °C. These mean that the optical quality of NiO films is improved by sintering. 相似文献
4.
Titanium nitride (TiN) thin films were prepared by means of reactive DC sputtering on quartz and sapphire substrates. Structural, electrical and optical effects of deposition parameters such as thickness, substrate temperature, substrate bias voltage were studied. The effect of substrate temperature variations in the 100-300°C range and substrate bias voltage variations in the 0-200 V DC range for 45-180 nm thick TiN films were investigated. Temperature-dependent electrical resistivity in the 100-350 K range and optical transmission in the 300-1500 nm range were measured for the samples. In addition, structural and morphological properties were studied by means of XRD and STM techniques.The smoothest surface and the lowest electrical resistivity was recorded for the optimal samples that were biased at about Vs=−120 V DC. Unbiased films exhibited a narrow optical transmission window between 300 and 600 nm. However, the transmission became much greater with increasing bias voltage for the same substrate temperature. Furthermore, it was found that lower substrate temperatures produced optically more transparent films.Application of single layers of MgF2 antireflecting coating on optimally prepared TiN films helped increase the optical transmission in the visible region to more than 40% for 45 nm thick samples. 相似文献
5.
To examine variations in the transparent conducting properties after annealing at high temperatures, 300-nm thick Sb-doped Sn1 − xHfxO2 (x = 0.00-0.10) films were deposited onto silica glass substrates by the RF sputtering method and annealed in air up to 1000 °C at 200 °C increments. After annealing, all the Sb-doped SnO2 films were transparent and electrically conductive, but large cracks, which decreased the electrical conductivity, were generated in several films due to crystallization or the thermal expansion difference between the film and substrate. Only the film deposited at room temperature in an Ar and O2 mixed atmosphere did not crack after annealing, and its electrical conductivity exceeded 100 S cm− 1 even after annealing at 1000 °C in air. Hf-doping blue shifted the fundamental absorption edges in the UV region in the Sb-doped Sn1 − xHfxO2 films. Additionally, the optical transmission at 310 nm, T310, increased as the Hf concentration increased, whereas the electrical conductivity was inversely proportional to the Hf concentration. On the other hand, thinner films (150-nm thick) with x = 0.00 showed both a high electrical conductivity over 100 S cm− 1 and a high transparency T310 = 65% after high temperature annealing. 相似文献
6.
Lei ZhengXiaodong Su Jun FanYajie Chen Xiaoluan YangLixing You Vincent G. Harris 《Thin solid films》2012,520(9):3651-3656
Control of the in-plane crystallographic orientation of YBa2Cu3O7 − x (YBCO) films on (100) MgO substrates is of significant application value due to the selective enhancement of superconducting properties. In the present work, the preparation, crystallographic and superconducting properties of YBCO films deposited on MgO substrates are reported. Crystallographic in-plane orientation was realized by means of tailoring the pulsed laser deposition conditions and the use of interfacial buffering structures. Superconductiong properties were measured for films having different in-plane orienations. The results indicate that the 0° in-plane oriented films showed the highest current density of 1.62 MA/cm2 that was attributed to the elimination of high-angle grain boudaries. Additionally, the growth mechanism of YBCO films was discussed in terms of crystallographic and thermodynamic theory. 相似文献
7.
Thin films of Ge10Se90 − xTex (x = 0, 10, 20, 30, 40, 50) glassy alloys were deposited at three substrate temperatures (303 K, 363 K and 423 K) using conventional thermal evaporation technique at base pressure of ~ 10− 4 Pa. X-ray diffraction results show that films deposited at 303 K are of amorphous nature while films deposited at 363 K and 423 K are of polycrystalline nature. The optical parameters, refractive index and optical gap have been derived from the transmission spectra (using UV-Vis-NIR spectrophotometer) of the thin films in the spectral region 400-1500 nm. This has been observed that refractive index values remain almost constant while the optical gap is found to decrease considerably with the increase of substrate temperature. The decrease in optical gap is explained on the basis of change in nature of films, from amorphous to polycrystalline state, with the increase of substrate temperature. The optical gap has also been observed to decrease with the increase of Te content. 相似文献
8.
A. Abdolahzadeh ZiabariF.E. Ghodsi 《Thin solid films》2011,520(4):1228-1232
Nanocrystalline CdxZn1 − xO thin films with different Cd volume ratios in solution (x = 0, 0.25, 0.50, 0.75 and 1) have been deposited on glass substrate by sol-gel dip-coating method. The as-deposited films were subjected to drying and annealing temperatures of 275 °C and 450 °C in air, respectively. The prepared films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, UV-vis spectroscopy and dc-electrical measurements. The results show that the samples are polycrystalline and the crystallinity of the films enhanced with x. The average grain size is in the range of 20-53 nm. The atomic percent of Cd:Zn was found to be 9.50:1.04, 6.20:3.77 and 4.42:6.61 for x = 0.75, 0.50 and 0.25, respectively. It was observed that the transmittance and the band gap decreased as x increased. All the films exhibit n-type electrical conductivity. The resistivity (ρ) and mobility (μ) are in the range of 3.3 × 102 − 3.4 × 10− 3 Ω cm, and 1.5 − 45 cm2 V− 1 s− 1 respectively. The electron density lies between 1.26 × 1016 and 0.2 × 1020 cm− 3. 相似文献
9.
Transparent semiconductor thin films of Zn1 − xTixO (0 ≦ x ≦ 0.12) were deposited on alkali-free glass substrates by the sol-gel method. The effects of Ti addition on the crystallization, microstructure, optical properties and resistivity of ZnO thin films were investigated. The as-coated films were preheated at 300 °C, and then annealed at 500 °C in air ambiance. X-ray diffraction results showed all polycrystalline Zn1 − xTixO thin films with preferred orientation along the (002) plane. Ti incorporated within the ZnO thin films not only decreased surface roughness but also increased optical transmittance and electrical resistivity. In the present study, the Zn0.88Ti0.12O film exhibited the best properties, namely an average transmittance of 91.0% (an increase of ~ 12% over the pure ZnO film) and an RMS roughness value of 1.04 nm. 相似文献
10.
I. Valyukh S.V. GreenC.G. Granqvist G.A. NiklassonS. Valyukh H. Arwin 《Thin solid films》2011,519(9):2914-2918
Thin films of NixW1 − x oxides with x = 0.05, 0.19, 0.43 and 0.90 were studied. Films with thicknesses in the range 125-250 nm were deposited on silicon wafers at room temperature by reactive DC magnetron co-sputtering from targets of Ni and W. The films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), and spectroscopic ellipsometry (SE). XRD spectra and SEM micrographs showed that all films were amorphous and possessed a columnar structure. The ellipsometric angles Ψ and Δ of as-deposited films were measured by a rotating analyzer ellipsometer in the UV-visible-near infrared range (0.63-6.18 eV) and by an infrared Fourier transform rotating compensator ellipsometer in the 500-5200 cm−1 wavenumber range. SE measurements were performed at angles of incidence of from 50 ° to 70 °. Parametric models were used to extract thicknesses of the thin films and overlayers of NixW1 − x oxide at different compositions, band gaps and optical constants. Features in the optical spectra of the NixW1 − x oxides were compared with previous data on tungsten oxide, nickel oxide and nickel tungstate. 相似文献
11.
The structure, optical and electrical properties of transparent conducting oxide films depend greatly on the methods of preparation, heat treatment, type and level of dopant. Thin films of (CdO)1−x(In2O3)x have been grown by electron beam evaporation technique for different concentrations of In2O3 (x = 0, 0.05, 0.1, 0.15 and 0.2). Increase of doping led to increased carrier concentration as derived from optical data and hence to increased electrical conductivity, which degraded the transparency of the films. An improvement of the electrical and optical properties of Cadmium indium oxide (CdIn2O4) has been achieved by post-deposition annealing. A resistivity value of 7 × 10− 5 Ω cm and transmittance of 92% in the near infrared region and 82% in the visible region have been obtained after annealing at 300 °C for 90 min in air. 相似文献
12.
Thin films of Cu2Te were deposited, at room temperature, on glass substrates by magnetron sputtering from independent Cu and Te sources. This work presents the effect of annealing temperature on the optical, structural, and electrical properties of sputtered Cu2Te films. Annealing above 300 °C resulted in stoichiometric and near stoichiometric Cu2Te phases, whereas temperatures above 400 °C yielded films with single Cu2Te phase. In contrast, annealing at temperatures of 250 °C and below resulted in mixed phases of CuTe, Cu7Te5, Cu1.8Te, and Cu2Te. Analyses of transmittance and reflectance measurements for Cu2Te indicate that photon absorption occurs via indirect band transitions for incident photons with energy above the band gap energy and free carrier absorption below the band gap energy. The determined indirect band gap was 0.90 eV and its associated phonon energy was 0.065 eV. Optical phonon scattering was identified as the mechanism through which the momentum is conserved during absorption by free carriers. Electrical measurements show p-type conductivity and highly degenerate semiconducting behavior with a hole carrier concentration p = 5.18 × 1021 cm− 3. 相似文献
13.
The Mn-doped ZnO (Zn1 − xMnxO) thin films with manganese compositions in the range of 0-8 at.% were deposited by radio-frequency (RF) magnetron sputtering on quartz glass substrates at room temperature (RT). The influence of Mn concentration on the structural, electrical and optical properties of Zn1 − xMnxO films has been investigated. X-ray diffraction (XRD) measurements reveal that all the films are single phase and have wurtzite structure with (002) c-axis orientation. The chemical states of Mn have been identified as the divalent state of Mn2+ ions in ZnO lattice. As the content of Mn increases, the c-lattice constant and the optical band gap of the films increase while the crystalline quality deteriorates gradually. Hall-effect measurements reveal that all the films are n-type and the conductivity of the films has a severe degradation with Mn content. It is also found that the intensity of RT photoluminescence spectra (PL) is suppressed and saturates with Mn doping. 相似文献
14.
Silicon nitride thin films for use as passivation layers in solar cells and organic electronics or as gate dielectrics in thin-film transistors were deposited by the Hot-wire chemical vapor deposition technique at a high deposition rate (1-3 ?/s) and at low substrate temperature. Films were deposited using NH3/SiH4 flow rate ratios between 1 and 70 and substrate temperatures of 100 °C and 250 °C. For NH3/SiH4 ratios between 40 and 70, highly transparent (T ~ 90%), dense films (2.56-2.74 g/cm3) with good dielectric properties and refractive index between 1.93 and 2.08 were deposited on glass substrates. Etch rates in BHF of 2.7 ?/s and < 0.5 ?/s were obtained for films deposited at 100 °C and 250 °C, respectively. Films deposited at both substrate temperatures showed electrical conductivity ~ 10− 14 Ω− 1 cm− 1 and breakdown fields > 10 MV cm− 1. 相似文献
15.
In this work, we present a sol-gel method for the preparation of zirconia films. Using zirconium n-propoxide as the starting precursor, a ZrO2 sol has been synthesized that remains stable for several months. Thin films were deposited using the dip-coating method. The structural characterization was performed using waveguide Raman spectroscopy. The films present an amorphous phase up to an annealing temperature of 400 °C. Both monoclinic and tetragonal phases were obtained for annealing temperatures higher than 450 °C. The proportions of these two phases were calculated from the Raman spectra and the size of the crystallites was evaluated using the low-wavenumber Raman band. The optical properties were characterized by the m-lines technique (n = 1.96) and UV-visible spectroscopy. The optical losses for a TE0 mode were measured to be 0.29 ± 0.03 dB cm− 1 for a sample annealed at 400 °C. To optimize the protocol for thermal annealing, a powder obtained from a dried sol was characterized by Thermal Gravimetric Analysis. Rutherford Back Scattering was employed to determine the chemical composition and the stoichiometry of the zirconia films. 相似文献
16.
Ramakanta Naik 《Thin solid films》2010,518(19):5437-5441
In this paper, we report results of the optical properties of thermally deposited As2 − xS3 − xSbx thin films with x = 0.02, 0.07, 0.1 and 0.15. We have characterized the deposited films by Fourier Transform Infrared, Raman and X-ray photoelectron spectroscopy (XPS). The relationship between the structural and optical properties and the compositional variation were investigated. It was found that the optical bandgap decreases with increase in Sb content. The XPS core level spectra show a decrease in As2S3 percentage with increase in Sb content. This is confirmed from the shifting of the Raman peak from AsS3 vibrational mode towards SbS3 vibrational mode. 相似文献
17.
Polycrystalline VOx thin films that were prepared for thermal-sensitive material of far infrared sensor had been deposited on Si substrates by ion beam sputtering deposition. Scanning electron microscopy images indicated that VOx thin films (oxygen pressure of 1.5×10−3 Pa) were grown into compact and ultra-fine grains (?50 nm), the film surfaces seemed smooth and uniform. Four-point probe measurements showed that the homogeneity of the films was better than 98% in a size of 30×30 mm2. The four-point probe measurement on hot plate presented the sheet resistance and the temperature coefficient of resistance of the VOx thin film that were 50 kΩ/square and −0.021 K−1 at 28°C, respectively. In addition, some samples annealed in Ar atmosphere had their resistance decreased. Thus, vanadium oxide films containing more amount VO2 were obtained. 相似文献
18.
GaP1−xNx thin films were deposited on glass substrates by RF sputtering employing a nitrogen-argon atmosphere in a partial pressure of 2×10−2 Torr. We varied the growth temperature in the range 420-520 °C. The film's optical properties were studied by transmittance and absorbance spectroscopy. Characterization by scanning electron microscopy in cross-sectional view, atomic force microscopy, and X-ray diffraction was performed to determinate the film thickness, surface morphology, and crystal structure, respectively. Raman spectroscopy was employed to analyze the structural properties of samples. The GaP1−xNx films presented a cubic polycrystalline structure with a preferential orientation along the [1 1 1] direction. By varying the growth conditions we were able to change the band gap energy between 1.35 and 1.98 eV. 相似文献
19.
Jin Won Kim 《Thin solid films》2010,518(22):6514-6517
V-doped K0.5Bi4.5Ti4O15 (K0.5Bi4.5 − x/3Ti4 − xVxO15, KBTiV-x, x = 0.00, 0.01, 0.03, and 0.05) thin films were prepared on a Pt(111)/Ti/SiO2/Si(100) substrate by a chemical solution deposition method. The thin films were annealed by using a rapid thermal annealing process at 750 °C for 3 min in an oxygen atmosphere. Among them, KBTiV-0.03 thin film exhibited the most outstanding electrical properties. The value of remnant polarization (2Pr) was 75 μC/cm2 at an applied electric field of 366 kV/cm. The leakage current density of the thin film capacitor was 5.01 × 10−8 at 100 kV/cm, which is approximately one order of magnitude lower than that of pure K0.5Bi4.5Ti4O15 thin film capacitor. We found that V doping is an effective method for improving the ferroelectric properties of K0.5Bi4.5Ti4O15 thin film. 相似文献
20.
Sin-Liang Ou Po-Cheng Kuo Shu-Chi Sheu Ger-Pin Lin Tsung-Lin Tsai Sheng-Chi Chen Don-Yau Chiang Wei-Tai Tang 《Materials & Design》2010
The (In15Sb85)100−xBix films (x = 0–18.3) were deposited on nature oxidized Si wafer and glass substrate at room temperature by magnetron co-sputtering of Sb target and InBi composite target. The optical and thermal properties of the films were examined by reflectivity thermal analyzer. Microstructures of the films were analyzed by X-ray diffraction and transmission electron microscope. The crystallization activation energy of the (In15Sb85)100−xBix film (x = 0–18.3) was decreased with increasing Bi content, this indicated that the crystallization speed was improved by doping Bi. The structure of as-deposited (In15Sb85)100−xBix films was amorphous and it would transform to Sb, InSb, Bi, and BiIn2 coexisting phases after annealing at 250 °C for 30 min. 相似文献