To deposit TiO2 films through plasma CVD, the partial pressure ratio of O2 to TIC14 should be greater than the stoichiometric ratio （PO2/PTiCl4 〉 1）. However, this may lead to the formation of powder instead of fil...To deposit TiO2 films through plasma CVD, the partial pressure ratio of O2 to TIC14 should be greater than the stoichiometric ratio （PO2/PTiCl4 〉 1）. However, this may lead to the formation of powder instead of film on the substrate when using volume dielectric barrier discharge （volume-DBD） at atmospheric pressure. In this study, by adding N2 into the working gas Ar, TiO2 photocatalytic films were successfully fabricated in the presence of excess O2 （PO2/PTiC14 = 2.6） by using a wire-to-plate atmospheric-pressure volume-DBD. The tuning effect of N2 on the deposition of TiO2 film was studied in detail. The results showed that by increasing the N2 content, the deposition rate and particle size of the TiO2 film were reduced, and its photocatalytic activity was enhanced. The tuning mechanism of N2 is further discussed.展开更多
The symmetric deposition technique is often used to improve the uniformity of sculptured thin film （STF）. In this paper, optical properties of STF with the columnar angles 4-/3 are analyzed theoretically, based on t...The symmetric deposition technique is often used to improve the uniformity of sculptured thin film （STF）. In this paper, optical properties of STF with the columnar angles 4-/3 are analyzed theoretically, based on the characteristic matrix method for extraordinary waves. Then, the transmittances of uniformity monolayer and bilayer STF in symmetrical style are calculated to show the effect of the bilayer structure on the optical properties of STF. The inhomogeneity of STF is involved in analyzing the differences in transmittance and phase retardation between monolayer and bilayer STF deposited in symmetric style. The results show that optical homogeneity of STF can be improved by depositing in symmetric style at the normal incidence, but it is not the same case as the oblique incidence.展开更多
The diamond films have been deposited by the hot filament CVD method on molybdenum substrates from the mixture reactant gas of acetone and hydrogen.The surface morphologies of the obtained diamond films under various ...The diamond films have been deposited by the hot filament CVD method on molybdenum substrates from the mixture reactant gas of acetone and hydrogen.The surface morphologies of the obtained diamond films under various deposition conditions have been observed by scanning electron microscope(SEM).The experimental results strongly indicate that the surface morphologies of the resulting films have closely related to the deposition conditions,i.e.,reaction pressure.For molybdenum substrates,under the lower reaction pressure the surface morphologies of the grains comprising the resulting films mainly display the small single crystal cubo-octahedron and double small crystal cubo-octahedron;under the higher reaction pressure,the surface morphologies mainly display the large cauliflower-like.These results show that there are various crystal habits for CVD diamond under various deposition conditions.展开更多
The preparation of PT/PEK c films is reported as well as their dielectric and optical properties. The c axis orientation ratio of the films is 68%. Dielectric constant and loss factor at 10 kHz is about 4.023 F/m and ...The preparation of PT/PEK c films is reported as well as their dielectric and optical properties. The c axis orientation ratio of the films is 68%. Dielectric constant and loss factor at 10 kHz is about 4.023 F/m and 0.003, respectively. The refractive indices of the films, n e and n o, are 1.657 3 and 1.627 8 at 0.63 μm wavelength, respectively. The optical band gap of the film with a thickness of 2.33 μm is found to be 3.06 eV.展开更多
Fluorinated amorphous hydrogenated a-C∶F∶H carbon thin films were deposited using radio frequency plasma enhanced chemical vapor deposition（RF-PECVD） reactor with CF4 and CH4 as source gases and were annealed in a...Fluorinated amorphous hydrogenated a-C∶F∶H carbon thin films were deposited using radio frequency plasma enhanced chemical vapor deposition（RF-PECVD） reactor with CF4 and CH4 as source gases and were annealed in a N2 atmosphere. The properties of these films were evaluated by FTIR spectrometry, UV-VIS spectrophotometry and single-wavelength spectroscopic ellipsometry. A correspondence relativity connection between the deposition rate and technology was found. The chemical bonding structures and the content of CHx and CFx in the films are transformed and the optical band gap decreases monotonically with increasing temperature after annealing. The dielectric constant is increased with decreasing content of F in the films and the optical band gap is decreased with decreasing the content of H in the film.展开更多
Thin films of hydrazine molybdenum （MoO4N4H6）, a new inorganic azo dye, were synthesized and deposited on a commercial glass substrate using the chemical bath deposition technique. Subsequently, the optical transmis...Thin films of hydrazine molybdenum （MoO4N4H6）, a new inorganic azo dye, were synthesized and deposited on a commercial glass substrate using the chemical bath deposition technique. Subsequently, the optical transmission, reflectivity, absorption, refractive index, and dielectric constant of hydrazine molybdenum were investigated using an ultraviolet-visible spectrophotometer. In addition, the film structure was analyzed by mid-infrared spectroscopy. The spectra of the films were found to be in line with those in the literature. The surface properties of all films were examined using a computer-controlled digital scanning electron microscope with a secondary electron detector. The areas of application and the technological advantages of this material were also considered.展开更多
Transmittance and chromaticity are essential requirements for optical performance of thin-film transistor(TFT)arrays.However,it is still a challenge to get high transmittance and excellent chromaticity at the same tim...Transmittance and chromaticity are essential requirements for optical performance of thin-film transistor(TFT)arrays.However,it is still a challenge to get high transmittance and excellent chromaticity at the same time.In this paper,optimized optical design by using antireflection film theory and optical phase modulation is demonstrated in low temperature poly-silicon(LTPS)TFT arrays.To realize high transmittance,the refractive index difference of adjacent films is modified by using silicon oxynitride(SiOxNy)with adjustable refractive index.To realize excellent chromaticity,the thicknesses of multilayer films are precisely regulated for antireflection of certain wavelength light.The results show that the transmittance and chromaticity have been improved by about 6%and 18‰,respectively,at the same time,which is a big step forward for high optical performance of TFT arrays.The device characteristics of the TFT arrays with the optimal design,such as threshold voltage and electron mobility,are comparable to those of conventional TFT arrays.The optimized optical design results in enhanced power-conversion efficiencies and perfects the multilayer film design on the basic theory,which has great practicability to be applied in TFT arrays.展开更多
基金supported by National Natural Science Foundation of China(Nos.10835004,51077009)the Fundamental Research Funds for the Central Universities
文摘To deposit TiO2 films through plasma CVD, the partial pressure ratio of O2 to TIC14 should be greater than the stoichiometric ratio （PO2/PTiCl4 〉 1）. However, this may lead to the formation of powder instead of film on the substrate when using volume dielectric barrier discharge （volume-DBD） at atmospheric pressure. In this study, by adding N2 into the working gas Ar, TiO2 photocatalytic films were successfully fabricated in the presence of excess O2 （PO2/PTiC14 = 2.6） by using a wire-to-plate atmospheric-pressure volume-DBD. The tuning effect of N2 on the deposition of TiO2 film was studied in detail. The results showed that by increasing the N2 content, the deposition rate and particle size of the TiO2 film were reduced, and its photocatalytic activity was enhanced. The tuning mechanism of N2 is further discussed.
基金supported by the National Natural Science Foundation of China(Grant No.61205211)
文摘The symmetric deposition technique is often used to improve the uniformity of sculptured thin film （STF）. In this paper, optical properties of STF with the columnar angles 4-/3 are analyzed theoretically, based on the characteristic matrix method for extraordinary waves. Then, the transmittances of uniformity monolayer and bilayer STF in symmetrical style are calculated to show the effect of the bilayer structure on the optical properties of STF. The inhomogeneity of STF is involved in analyzing the differences in transmittance and phase retardation between monolayer and bilayer STF deposited in symmetric style. The results show that optical homogeneity of STF can be improved by depositing in symmetric style at the normal incidence, but it is not the same case as the oblique incidence.
文摘The diamond films have been deposited by the hot filament CVD method on molybdenum substrates from the mixture reactant gas of acetone and hydrogen.The surface morphologies of the obtained diamond films under various deposition conditions have been observed by scanning electron microscope(SEM).The experimental results strongly indicate that the surface morphologies of the resulting films have closely related to the deposition conditions,i.e.,reaction pressure.For molybdenum substrates,under the lower reaction pressure the surface morphologies of the grains comprising the resulting films mainly display the small single crystal cubo-octahedron and double small crystal cubo-octahedron;under the higher reaction pressure,the surface morphologies mainly display the large cauliflower-like.These results show that there are various crystal habits for CVD diamond under various deposition conditions.
文摘The preparation of PT/PEK c films is reported as well as their dielectric and optical properties. The c axis orientation ratio of the films is 68%. Dielectric constant and loss factor at 10 kHz is about 4.023 F/m and 0.003, respectively. The refractive indices of the films, n e and n o, are 1.657 3 and 1.627 8 at 0.63 μm wavelength, respectively. The optical band gap of the film with a thickness of 2.33 μm is found to be 3.06 eV.
文摘Fluorinated amorphous hydrogenated a-C∶F∶H carbon thin films were deposited using radio frequency plasma enhanced chemical vapor deposition（RF-PECVD） reactor with CF4 and CH4 as source gases and were annealed in a N2 atmosphere. The properties of these films were evaluated by FTIR spectrometry, UV-VIS spectrophotometry and single-wavelength spectroscopic ellipsometry. A correspondence relativity connection between the deposition rate and technology was found. The chemical bonding structures and the content of CHx and CFx in the films are transformed and the optical band gap decreases monotonically with increasing temperature after annealing. The dielectric constant is increased with decreasing content of F in the films and the optical band gap is decreased with decreasing the content of H in the film.
文摘Thin films of hydrazine molybdenum （MoO4N4H6）, a new inorganic azo dye, were synthesized and deposited on a commercial glass substrate using the chemical bath deposition technique. Subsequently, the optical transmission, reflectivity, absorption, refractive index, and dielectric constant of hydrazine molybdenum were investigated using an ultraviolet-visible spectrophotometer. In addition, the film structure was analyzed by mid-infrared spectroscopy. The spectra of the films were found to be in line with those in the literature. The surface properties of all films were examined using a computer-controlled digital scanning electron microscope with a secondary electron detector. The areas of application and the technological advantages of this material were also considered.
基金This work was supported by the Shenzhen Science and Technology Innovation(Grant No.JCYJ20180507181702150)the Guangdong Science and Technology Plan Project(Grant No.2019A050510011)the National Natural Science Foundation of China(Grant No.61504004).
文摘Transmittance and chromaticity are essential requirements for optical performance of thin-film transistor(TFT)arrays.However,it is still a challenge to get high transmittance and excellent chromaticity at the same time.In this paper,optimized optical design by using antireflection film theory and optical phase modulation is demonstrated in low temperature poly-silicon(LTPS)TFT arrays.To realize high transmittance,the refractive index difference of adjacent films is modified by using silicon oxynitride(SiOxNy)with adjustable refractive index.To realize excellent chromaticity,the thicknesses of multilayer films are precisely regulated for antireflection of certain wavelength light.The results show that the transmittance and chromaticity have been improved by about 6%and 18‰,respectively,at the same time,which is a big step forward for high optical performance of TFT arrays.The device characteristics of the TFT arrays with the optimal design,such as threshold voltage and electron mobility,are comparable to those of conventional TFT arrays.The optimized optical design results in enhanced power-conversion efficiencies and perfects the multilayer film design on the basic theory,which has great practicability to be applied in TFT arrays.
