Low pressure metalorganic chemical vapour deposition （LP-MOCVD） growth and characteristics of InAsSb on （100） GaSb substrates are investigated. Mirror-like surfaces with a minimum lattice mismatch are obtained. Th...Low pressure metalorganic chemical vapour deposition （LP-MOCVD） growth and characteristics of InAsSb on （100） GaSb substrates are investigated. Mirror-like surfaces with a minimum lattice mismatch are obtained. The samples are studied by photoluminescence spectra, and the output is 3.17μm in wavelength. The surface of InAsSb epilayer shows that its morphological feature is dependent on buffer layer. With an InAs buffer layer used, the best surface is obtained. The InAsSb film shows to be of n-type conduction with an electron concentration of 8.52 × 10^16 cm^-3.展开更多
The single solid source precursor, cobalt （Ⅱ） acetylacetonate was prepared and characterized by infrared spectroscopy. Thin films of cobalt oxide were deposited on soda lime glass substrates through the pyrolysis ...The single solid source precursor, cobalt （Ⅱ） acetylacetonate was prepared and characterized by infrared spectroscopy. Thin films of cobalt oxide were deposited on soda lime glass substrates through the pyrolysis （metal organic chemical vapour deposition （MOCVD）） of single solid source precursor, cobalt acetylacetonate, Co[C5H7O2]2 at a temperature of 420℃. The compositional characterization carried out by rutherford backscattering spectroscopy and X-ray diffraction （XRD）, showed that the films have a stoichiometry of Co2O3 and an average thickness of 227±0.2 nm. A direct energy gap of 2,15±0.01 eV was calculated by the data obtained by optical absorption spectroscopy. The morphology of the films obtained by scanning electron microscopy, showed that the grains were continuous and uniformly distributed at various magnifications, while the average grain size was less than i micron for the deposited thin films of cobalt oxide.展开更多
Thin films of copper titanium oxide were deposited by metal organic chemical vapour deposition technique from the synthesized single solid source precursor, copper titanium acetylacatonate Cu [Ti(C5H7O2)3] at the depo...Thin films of copper titanium oxide were deposited by metal organic chemical vapour deposition technique from the synthesized single solid source precursor, copper titanium acetylacatonate Cu [Ti(C5H7O2)3] at the deposition temperature of 420°C. The deposited films were characterized using Rutherford Backscattering Spectroscopy, Scanning Electron Microscopy with Energy Dispersive X-Ray facility attached to it, X-Ray Diffractometry, UV-Visible Spectrometry and van-der Pauw Conductivity measurement. Results show that the thickness of the prepared film is determined as 101.236 nm and the film is amorphous in structure, having average grain size of approximately 1 μm. The optical behaviour showed that the absorption edge of the film was at 918 nm near infrared with corresponding direct energy band gap of 1.35 eV. The electrical characterization of the film gave the values of resistivity, sheet resistance and conductivity of the film as 3.43 × 10-1 Ω-cm, 3.39 × 106 Ω/square and 2.91 (Ω-cm)-1 respectively.展开更多
A single solid source precursor bis-(morpholinodithioato-s,s’)-Mo was prepared and molybdenum sulphide thin film was deposited on sodalime glass using Metal Organic Chemical Vapour Deposition (MOCVD) technique at dep...A single solid source precursor bis-(morpholinodithioato-s,s’)-Mo was prepared and molybdenum sulphide thin film was deposited on sodalime glass using Metal Organic Chemical Vapour Deposition (MOCVD) technique at deposition temperature of 420?C. The film was characterized using Rutherford Backscattering Spectroscopy (RBS), Ultraviolet-Visible Spectroscopy, Four point probe technique, Scanning Electron Mi-croscopy (SEM), X-ray Diffractometry (XRD) and Atomic Force Microscopy (AFM). A direct optical band gap of 1.77 eV was obtained from the analysis of the absorption spectrum. The sheet resistance was found to be of the order of 10P–5P ΩP–1P?cmP–1P. SEM micrographs of the films showed the layered structure of the film with an estimated grain size that is less than 2 μm while XRD indicates parallel orientation of the basal plane to the substrate surface.展开更多
Molybdenum oxodithiocarbamate was prepared as thin films which were deposited on sodalime glass a single solid source precursor for molybdenum oxysulphide substrates using metal organic chemical vapour deposition （MO...Molybdenum oxodithiocarbamate was prepared as thin films which were deposited on sodalime glass a single solid source precursor for molybdenum oxysulphide substrates using metal organic chemical vapour deposition （MOCVD） technique at a temperature of 420~C. Rutherford backscattering spectroscopy （RBS） was used to determine the elemental composition of the film which showed that the films contained large amounts of oxygen. The large amount of oxygen was attributed to the large abundance of oxygen in the starting material. A direct optical energy gap of 3.31 eV was obtained from the analysis of the absorption spectrum. The scanning electron microscopy （SEM） micrographs of the films showed that the films were continuous and porous. An estimated average size of the grains was below 5 #m. X-ray diffraction （XRD） showed that the deposited films were crystalline in nature.展开更多
Introduction In;O;·Sn films have high transparency（>95％） within the visible spectral region, low resistivity(10;—10;ohm·cm) at room temperature and superior thermal stability. These films have been ap...Introduction In;O;·Sn films have high transparency（>95％） within the visible spectral region, low resistivity(10;—10;ohm·cm) at room temperature and superior thermal stability. These films have been applied to solar cells, electronics and photoelectronics fields. In recent years, organometallic-CVD method has emerged as a successful alternate to the physical methods and general CVD for the growth of these films. The MO-CVD tech-展开更多
A Zinc(II) complex of hexamethylenetetramine was prepared as a single source precursor and used to deposit zinc oxynitride thin films. The thin films were deposited on soda-lime glass substrates using the Metal Organi...A Zinc(II) complex of hexamethylenetetramine was prepared as a single source precursor and used to deposit zinc oxynitride thin films. The thin films were deposited on soda-lime glass substrates using the Metal Organic Chemical Vapour Deposition (MOCVD) technique at the deposition temperature of 370°C and 390°C, respectively. The Fourier Transform Infrared Spectroscopy (FTIR) was used to determine the functional groups in the precursor, with stretching frequency for O-H, N-H, and C-H observed. The deposited films were characterized using UV-Visible Spectroscopy, Scanning Electron Microscopy (SEM), Elemental diffraction X-ray (EDX), and X-ray Diffractometer (XRD). A direct bandgap of 3.15 eV and 3.18 eV was obtained from the film deposited at 370°C and 390°C, respectively, using the Envelope Method. In comparison, a bandgap of 3.19 eV and 3.21 eV was obtained using the absorption spectrum fitting (ASF) method. The SEM revealed that the film is homogeneous, dense, and compact, composed of cluster grains. The EDX confirmed the presence of Zinc, Nitrogen and Oxygen. The X-ray Diffraction indicated the polycrystalline nature of the film.展开更多
基金Project supported by the National High Technology Research and Development Program of China (Grant No 2005A000200)the West Light Plan of China (Grant No 2005ZD01)the Xi’an Applied Materials Innovation Fund of China (Grant No XA-AM-200613)
文摘Low pressure metalorganic chemical vapour deposition （LP-MOCVD） growth and characteristics of InAsSb on （100） GaSb substrates are investigated. Mirror-like surfaces with a minimum lattice mismatch are obtained. The samples are studied by photoluminescence spectra, and the output is 3.17μm in wavelength. The surface of InAsSb epilayer shows that its morphological feature is dependent on buffer layer. With an InAs buffer layer used, the best surface is obtained. The InAsSb film shows to be of n-type conduction with an electron concentration of 8.52 × 10^16 cm^-3.
基金the Third World Academy of Science (TWAS, Grant #93-058 R6/PHYS/AF/AC)Obafemi Awolowo University(University Research Committee URC) for supporting this project
文摘The single solid source precursor, cobalt （Ⅱ） acetylacetonate was prepared and characterized by infrared spectroscopy. Thin films of cobalt oxide were deposited on soda lime glass substrates through the pyrolysis （metal organic chemical vapour deposition （MOCVD）） of single solid source precursor, cobalt acetylacetonate, Co[C5H7O2]2 at a temperature of 420℃. The compositional characterization carried out by rutherford backscattering spectroscopy and X-ray diffraction （XRD）, showed that the films have a stoichiometry of Co2O3 and an average thickness of 227±0.2 nm. A direct energy gap of 2,15±0.01 eV was calculated by the data obtained by optical absorption spectroscopy. The morphology of the films obtained by scanning electron microscopy, showed that the grains were continuous and uniformly distributed at various magnifications, while the average grain size was less than i micron for the deposited thin films of cobalt oxide.
文摘Thin films of copper titanium oxide were deposited by metal organic chemical vapour deposition technique from the synthesized single solid source precursor, copper titanium acetylacatonate Cu [Ti(C5H7O2)3] at the deposition temperature of 420°C. The deposited films were characterized using Rutherford Backscattering Spectroscopy, Scanning Electron Microscopy with Energy Dispersive X-Ray facility attached to it, X-Ray Diffractometry, UV-Visible Spectrometry and van-der Pauw Conductivity measurement. Results show that the thickness of the prepared film is determined as 101.236 nm and the film is amorphous in structure, having average grain size of approximately 1 μm. The optical behaviour showed that the absorption edge of the film was at 918 nm near infrared with corresponding direct energy band gap of 1.35 eV. The electrical characterization of the film gave the values of resistivity, sheet resistance and conductivity of the film as 3.43 × 10-1 Ω-cm, 3.39 × 106 Ω/square and 2.91 (Ω-cm)-1 respectively.
文摘A single solid source precursor bis-(morpholinodithioato-s,s’)-Mo was prepared and molybdenum sulphide thin film was deposited on sodalime glass using Metal Organic Chemical Vapour Deposition (MOCVD) technique at deposition temperature of 420?C. The film was characterized using Rutherford Backscattering Spectroscopy (RBS), Ultraviolet-Visible Spectroscopy, Four point probe technique, Scanning Electron Mi-croscopy (SEM), X-ray Diffractometry (XRD) and Atomic Force Microscopy (AFM). A direct optical band gap of 1.77 eV was obtained from the analysis of the absorption spectrum. The sheet resistance was found to be of the order of 10P–5P ΩP–1P?cmP–1P. SEM micrographs of the films showed the layered structure of the film with an estimated grain size that is less than 2 μm while XRD indicates parallel orientation of the basal plane to the substrate surface.
基金the Third World Academy of Science (TWAS,No.93-058R6/PHYS/AF/AC) Italy and Obafemi Awolowo University (University Research Committee (URC)) for support-ing this project
文摘Molybdenum oxodithiocarbamate was prepared as thin films which were deposited on sodalime glass a single solid source precursor for molybdenum oxysulphide substrates using metal organic chemical vapour deposition （MOCVD） technique at a temperature of 420~C. Rutherford backscattering spectroscopy （RBS） was used to determine the elemental composition of the film which showed that the films contained large amounts of oxygen. The large amount of oxygen was attributed to the large abundance of oxygen in the starting material. A direct optical energy gap of 3.31 eV was obtained from the analysis of the absorption spectrum. The scanning electron microscopy （SEM） micrographs of the films showed that the films were continuous and porous. An estimated average size of the grains was below 5 #m. X-ray diffraction （XRD） showed that the deposited films were crystalline in nature.
基金Supported by the National Natural Science Foundation of China
文摘Introduction In;O;·Sn films have high transparency（>95％） within the visible spectral region, low resistivity(10;—10;ohm·cm) at room temperature and superior thermal stability. These films have been applied to solar cells, electronics and photoelectronics fields. In recent years, organometallic-CVD method has emerged as a successful alternate to the physical methods and general CVD for the growth of these films. The MO-CVD tech-
文摘A Zinc(II) complex of hexamethylenetetramine was prepared as a single source precursor and used to deposit zinc oxynitride thin films. The thin films were deposited on soda-lime glass substrates using the Metal Organic Chemical Vapour Deposition (MOCVD) technique at the deposition temperature of 370°C and 390°C, respectively. The Fourier Transform Infrared Spectroscopy (FTIR) was used to determine the functional groups in the precursor, with stretching frequency for O-H, N-H, and C-H observed. The deposited films were characterized using UV-Visible Spectroscopy, Scanning Electron Microscopy (SEM), Elemental diffraction X-ray (EDX), and X-ray Diffractometer (XRD). A direct bandgap of 3.15 eV and 3.18 eV was obtained from the film deposited at 370°C and 390°C, respectively, using the Envelope Method. In comparison, a bandgap of 3.19 eV and 3.21 eV was obtained using the absorption spectrum fitting (ASF) method. The SEM revealed that the film is homogeneous, dense, and compact, composed of cluster grains. The EDX confirmed the presence of Zinc, Nitrogen and Oxygen. The X-ray Diffraction indicated the polycrystalline nature of the film.
