We report the performances of a chalcopyrite Cu(In, Ga)Se<sub>2 </sub>CIGS-based thin-film solar cell with a newly employed high conductive n-Si layer. The data analysis was performed with the help of the ...We report the performances of a chalcopyrite Cu(In, Ga)Se<sub>2 </sub>CIGS-based thin-film solar cell with a newly employed high conductive n-Si layer. The data analysis was performed with the help of the 1D-Solar Cell Capacitance Simulator (1D-SCAPS) software program. The new device structure is based on the CIGS layer as the absorber layer, n-Si as the high conductive layer, i-In<sub>2</sub>S<sub>3</sub>, and i-ZnO as the buffer and window layers, respectively. The optimum CIGS bandgap was determined first and used to simulate and analyze the cell performance throughout the experiment. This analysis revealed that the absorber layer’s optimum bandgap value has to be 1.4 eV to achieve maximum efficiency of 22.57%. Subsequently, output solar cell parameters were analyzed as a function of CIGS layer thickness, defect density, and the operating temperature with an optimized n-Si layer. The newly modeled device has a p-CIGS/n-Si/In<sub>2</sub>S<sub>3</sub>/Al-ZnO structure. The main objective was to improve the overall cell performance while optimizing the thickness of absorber layers, defect density, bandgap, and operating temperature with the newly employed optimized n-Si layer. The increase of absorber layer thickness from 0.2 - 2 µm showed an upward trend in the cell’s performance, while the increase of defect density and operating temperature showed a downward trend in solar cell performance. This study illustrates that the proposed cell structure shows higher cell performances and can be fabricated on the lab-scale and industrial levels.展开更多
The“People’s Films,”when examined from the perspective of classical aesthetics,present a unique visual style that creates artistic conceptions through sparse filming and deliver a scenery-based ideology through bac...The“People’s Films,”when examined from the perspective of classical aesthetics,present a unique visual style that creates artistic conceptions through sparse filming and deliver a scenery-based ideology through background shots,contributing to the overall aesthetic taste dominated by plainness.Chinese national aesthetic tastes,distinguished by implicitness,symbolism,and ethereality,have the magical power to present charming conceptions via plain and simple scenes,thus endowing the“People’s Films”with natural,plain,and harmonious frames that are unique to China.Behind the silent and plain scenes are representations of personal cultivation and essential values cherished by the Chinese people,which are achieved via the momentary presence and entirety of scenes photographed in the films,delivering an internal transcendence of people’s consciousness.展开更多
Sb<sub>2</sub>S<sub>3</sub> has gained tremendous research recently for thin film solar cell absorber material because of their easy synthesis, unique electrical and optical properties. The sto...Sb<sub>2</sub>S<sub>3</sub> has gained tremendous research recently for thin film solar cell absorber material because of their easy synthesis, unique electrical and optical properties. The stoichiometry and composition of electroless Sb<sub>2</sub>S<sub>3</sub> thin films were analyzed using XPS depth profile studies. The surface layers were found nearly stoichiometric. On the other hand, the inner layer was rich in antimony composition making it more conductive electrically.展开更多
Cd_(1-x)Zn_(x)S thin films were deposited by chemical bath deposition(CBD)on the glass substrate to study the influence of cadmium sulfate concentration on the structural characteristics of the thin film.The SEM resul...Cd_(1-x)Zn_(x)S thin films were deposited by chemical bath deposition(CBD)on the glass substrate to study the influence of cadmium sulfate concentration on the structural characteristics of the thin film.The SEM results show that the thin film surfaces under the cadmium sulfate concentration of 0.005 M exhibit better compactness and uniformity.The distribution diagrams of thin film elements illustrate the film growth rate changes on the trend of the increase,decrease,and increase with the increase of cadmium sulfate concentration.XRD studies exhibit the crystal structure of the film is the hexagonal phase,and there are obvious diffraction peaks and better crystallinity when the concentration is 0.005 M.Spectrophotometer test results demonstrate that the relationship between zinc content x and optical band gap value E_(g) can be expressed by the equation E_(g)(x)=0.59x^(2)+0.69x+2.43.Increasing the zinc content can increase the optical band gap,and the absorbance of the thin film can be improved by decreasing the cadmium sulfate concentration,however,all of them have good transmittance.At a concentration of 0.005 M,the thin film has good absorbance in the 300-800 nm range,80%transmittance,and band gap value of 3.24 eV,which is suitable for use as a buffer layer for solar cells.展开更多
Ag- and Sn-doped In2S3 thin films were deposited on glass substrates using the thermal evaporation technique. The doping was realized by thermal diffusion. The influences of Ag and Sn impurities on the electrical, str...Ag- and Sn-doped In2S3 thin films were deposited on glass substrates using the thermal evaporation technique. The doping was realized by thermal diffusion. The influences of Ag and Sn impurities on the electrical, structural, morphological, and optical properties of the In2S3 films were investigated. In all deposited samples, the x-ray diffraction spectra revealed the formation of cubic In2S3 phase. A significant increase in the crystallite size was observed after Ag doping,while the doping of Sn slightly decreased the crystallite size. The x-ray photoelectron spectroscopy verified the diffusion of Ag and Sn into the In2S3 films after annealing. The optical study illustrated that Ag doping resulted in a reduction of the optical band gap while Sn doping led to a widening of the gap. Optical properties were investigated to determine the optical constants. Besides, it was found that the resistivity decreases significantly either after Ag or Sn incorporation. The study demonstrates that the Sn-doped In2S3 thin films are more suitable for buffer layer application in solar cells than the Ag-doped In2S3 thin films.展开更多
The flat cylindrical indentation tests with different sizes of punch radius were investigated using finite element method (FEM) aimed to reveal the effect of punch size on the indentation behavior of the film/substr...The flat cylindrical indentation tests with different sizes of punch radius were investigated using finite element method (FEM) aimed to reveal the effect of punch size on the indentation behavior of the film/substrate system. Based on the FEM results analysis, two methods was proposed to separate film's reduced Young's modulus from a film/substrate system. The first method was based on a new weight function that quantifies film's and substrate's contributions to the overall mechanical properties of the film/substrate system in the flat cylindrical indentation test. The second method, a numerical approach, including fitting and extrapolation procedures was put forward. Both of the results from the two methods showed a reasonable agreement with the one input FE model. At last, the effect of maximum indentation depth and the surface micro-roughness of the thin film on the reduced Young's modulus of the film/substrate system were discussed. The methods proposed in the present study provide some new conceptions on evaluating other properties of thin films, e.g. creep, for which a flat-ended punch is also employed.展开更多
The primary objective of this study is to apply the Evaluation Grid Method(EGM)and the continuous fuzzy Kano quality model to explore the cognitive preferences of Taiwan China residents regarding the beauty of Taiwan...The primary objective of this study is to apply the Evaluation Grid Method(EGM)and the continuous fuzzy Kano quality model to explore the cognitive preferences of Taiwan China residents regarding the beauty of Taiwan’s China landscape paintings.The aim is to contribute to the development of social and cultural art and promote the widespread appeal of art products.Through a literature review,consultations with aesthetic experts,and the application of Miryoku Engineering’s EGM,this paper consolidates the factors that contribute to the attractiveness of painting art products among Taiwan China residents,taking into account various aesthetic qualities.Simultaneously,the paper introduces the use of the triangular fuzzy golden ratio scale semantics,specifically the equal-ratio aesthetic scale semantics,as a replacement for the traditional subjective consciousness model.Departing from the traditional discrete Kano model that employs the mode as the standard for evaluating quality,this study applies triangular fuzzy numbers to the continuous Kano quality model to analyze the diverse preferences and evaluation standards of the public.The hope is that this research methodology will not only deepen Taiwan China residents’understanding and aesthetic literacy of painting art but also serve as a reference for the popularization of art products.展开更多
The regeneration procedure of Q-state PbS particles in lead arachidate(PbAr)Langmuir-Blodgett films have been studied by means of UV-vis absorption, FT-IR spectra and quartz crystal microbalance(QCM) measurements.The ...The regeneration procedure of Q-state PbS particles in lead arachidate(PbAr)Langmuir-Blodgett films have been studied by means of UV-vis absorption, FT-IR spectra and quartz crystal microbalance(QCM) measurements.The results showed that the mole fraction of PbS particles in LB films was increased by immersing PbScontaining ArH LB films in a Pb ̄(2+) buffer solution,followed by being reexposed to H_2S gas.展开更多
Copper sulfide thin films are deposited onto different substrates at room temperature using the thermal evaporation technique. X-ray diffraction spectra show that the film has an orthorhombicchalcocite (7-Cu2S) phas...Copper sulfide thin films are deposited onto different substrates at room temperature using the thermal evaporation technique. X-ray diffraction spectra show that the film has an orthorhombicchalcocite (7-Cu2S) phase. The atomic force microscopy images indicate that the film exhibits nanoparticles with an average size of nearly 44 nm. Specrtophotometric measurements for the transmittance and reflectance are carried out at normal incidence in a spectral wavelength range of 450 nm-2500 nm. The refractive index, n, as well as the absorption index, k is calculated. Some dispersion parameters are determined. The analyses of el and e2 reveal several absorption peaks. The analysis of the spectral behavior of the absorption coefficient, c~, in the absorption region reveals direct and indirect allowed transitions. The dark electrical resistivity is studied as a function of film thickness and temperature. Tellier's model is adopted for determining the mean free path and bulk resistance.展开更多
Nanocrystalline copper oxide (CuO) thin films were deposited onto glass substrates by a spin coating technique using an aqueous solution of copper acetate. These films were characterized for their structural, mor-phol...Nanocrystalline copper oxide (CuO) thin films were deposited onto glass substrates by a spin coating technique using an aqueous solution of copper acetate. These films were characterized for their structural, mor-phological, optoelectronic properties by means of X-ray diffraction (XRD) scanning electron microscopy (SEM), UVspectroscopy and four probe method. The CuO films are oriented along (1 1 1) plane with the monoclinic crystal structure. These films were utilized in H2S sensors. The dependence of the H2S response on the operating temperature, H2S concentration of CuO film (annealed at 700。C) was investigated. The CuO film showed selectivity for H2S. The maximum H2S response of 25.2 % for the CuO film at gas concentra-tion of 100 ppm at operating temperature 200oC was achieved.展开更多
Thin films of ZnxCd1-xS have been prepared by electron beam evaporation of a mixture of ZnS & CdS powders. The films are deposited onto sodalime glass slides under similar conditions.The composition of the films i...Thin films of ZnxCd1-xS have been prepared by electron beam evaporation of a mixture of ZnS & CdS powders. The films are deposited onto sodalime glass slides under similar conditions.The composition of the films is varied from CdS to ZnS (x=0 to 1). The films show a regular change in color from toner red to orange yellow as Zn concentration increases to maximum.These films are characterized for their optical, electricaI and structural properties. The bandgap value of ZnxCd1-xS films is found to vary linearIy from 2.20 eV to 3.44 eV with change in the x value from 0 to 1. The resistivity of these films is in the range of 171.0 Ωcm to 5.5× 106Ωcm for x=0~0.6. All the samples show cubic structure after annealing in air at 250℃ for 40 min.The lattice constant ao varies from 0.5884 nm to 0.54109 nm linearly.展开更多
The structural and thermomechanical properties of starch-based plastic films reinforced with kaolin and metakaolin have been studied by various techniques (X-ray diffraction, IR-TF spectroscopy, scanning electron micr...The structural and thermomechanical properties of starch-based plastic films reinforced with kaolin and metakaolin have been studied by various techniques (X-ray diffraction, IR-TF spectroscopy, scanning electron microscopy, tensile tests, and thermal resistance). The results obtained showed that kaolin, an inert material, prevents the starch from losing its granular structure and to solubilize during the heating, generating plastic films of low Young’s modulus (7 MPa). On the other hand, metakaolin, an amorphous and dehydroxylated material obtained after heating of kaolin at 700°C for 1 hour, substantially improves the thermomechanical properties of the plastic films. The Young’s modulus increases from 19 MPa to 25 MPa while the thermal resistance increases from 90°C to 120°C. This was attributed to good dispersion of the metakaolin in the polymer matrix after the loss of the granular structure of the starch during heating.展开更多
In this study, In<sub>2</sub>S<sub>3</sub> thin films have been deposited on ITO and fluorine-tinoxide FTO coated glass substrates by single source vacuum thermal evaporation annealed in vacuum...In this study, In<sub>2</sub>S<sub>3</sub> thin films have been deposited on ITO and fluorine-tinoxide FTO coated glass substrates by single source vacuum thermal evaporation annealed in vacuum a 300°C - 400°C for 1 h. The samples structure was characterized by X-ray diffraction, revealing the quadratic structure of In<sub>2</sub>S<sub>3</sub> and the crystallinity depends on the temperature of annealing and nature of substrate. The various structural parameters, such as, crystalline size, dislocation density, strain and texture coefficient were calculated. The optical properties show that the refractive index dispersion data obeyed the single oscillator of the Wemple-DiDomenico model. By using this model, the dispersion parameters and the high-frequency dielectric constant were determined. The Hall Effect has been studied at room temperature. The Hall voltages, the Hall coefficient (RH) and mobility (μH) have been measured at different magnetic and electric fields. The films show n-type behavior irrespective of temperature and composition.展开更多
Chemical bath deposition technique has been used to deposit Ni-doped Sb2S3 thin films onto glass substrate. Doping was carried out by adding 1, 3 and 5 wt% of Ni. Bath temperature was kept as 10℃ and films were annea...Chemical bath deposition technique has been used to deposit Ni-doped Sb2S3 thin films onto glass substrate. Doping was carried out by adding 1, 3 and 5 wt% of Ni. Bath temperature was kept as 10℃ and films were annealed at 250℃ under vacuum. Polycrystalline nature of films with an orthorhombic phase was analyzed by X-ray diffraction technique. Scanning electron microscopy was used for morphological study which shows that grains are spherical. Optical measurements using transmittance data indicated that films have a direct band gap of 1.00 - 2.60 eV with an absorption coefficient of ~104 cm<sup>-1</sup> in visible range. The average value of electrical conductivity was calculated as 1.66, 1.11 and 1.06 (Ω·cm)<sup>-1</sup> for as-deposited films and 1.90, 2.08 and 1.15 (Ω·cm)<sup>-1</sup> for annealed films while refractive indices were found as 2.18 - 3.38 and 1.91 - 3.74 respectively. The obtained films can be used for solar cell applications due to their good absorbing properties like higher absorption coefficient and refractive index values.展开更多
Cu x S thin films are implanted by low energy N + ion beam. The influences of the energy and dose of N + ion implantation on Cu x S films are investigated. The results show that the ratio of copper to sulfur is increa...Cu x S thin films are implanted by low energy N + ion beam. The influences of the energy and dose of N + ion implantation on Cu x S films are investigated. The results show that the ratio of copper to sulfur is increased to some extent, the constituents of the film are turned to rich copper phase from rich sulfurous phase after ion beam irradiation. X-ray diffraction spectrum and optical transmission spectra of sample have confirmed the results.展开更多
The influence of thermal treatment on the lux-ampere characteristics of polycrystalline films from the CdSe<sub>x</sub>S<sub>1-x</sub> solid solution obtained by the method of thermal evaporati...The influence of thermal treatment on the lux-ampere characteristics of polycrystalline films from the CdSe<sub>x</sub>S<sub>1-x</sub> solid solution obtained by the method of thermal evaporation in a vacuum has been investigated. It is shown that at low illumination intensities L μ of electrons increases with a power law μ ~ L<sup>γ</sup>, first with the exponent γ > 1, then with γ ≈ 0.5, and their concentration n almost does not change. Starting from the intensity L > 12 - 15 lx, the electron concentration increases strongly n ~ L<sup>β</sup> from β ≈ 3.0, and the parameters n and μ reach relatively high values ~(10<sup>15</sup> - 10<sup>16</sup>) sm<sup>-3</sup> and ~(150 - 200) sm<sup>2</sup>/V·s, however further, at L > 50 lx, a weak dependence of n(L) and μ(L) with β, γ < 1.0 is found. The obtained experimental results are interpreted on the basis of a model of a semiconductor film with intergranular potential barriers when the concentration and barrier mechanisms of photoconductivity operate simultaneously.展开更多
BACKGROUND Barrett’s esophagus(BE)is a pre-malignant condition associated with the development of esophageal adenocarcinoma.The prevalence of BE in the general populations of Asian countries ranges from 0.06%to 1%.Ho...BACKGROUND Barrett’s esophagus(BE)is a pre-malignant condition associated with the development of esophageal adenocarcinoma.The prevalence of BE in the general populations of Asian countries ranges from 0.06%to 1%.However,with lifestyle changes in Asian countries and adoption of western customs,the prevalence of BE might have increased.AIM To determine the current prevalence of BE in Taiwan,and to investigate risk factors predicting the presence of BE.METHODS This retrospective study was conducted at the Health Evaluation Center of Kaohsiung Veterans General Hospital in Taiwan.Between January 2015 and December 2015,3385 subjects undergoing routine esophagogastroduodenoscopy examinations as part of a health check-up at the Health Evaluation Center were included.Patient characteristics and endoscopic findings were carefully reviewed.Lesions with endoscopic findings consistent with BE awaiting histological evaluation were judged as endoscopically suspected esophageal metaplasia(ESEM).BE was defined based on extension of the columnar epithelium≥1 cm above the gastroesophageal junction and was confirmed based on the presence of specialized intestinal metaplasia(IM)in the metaplastic esophageal epithelium.Clinical factors of subjects with BE and subjects without BE were compared,and the risk factors predicting BE were analyzed.RESULTS A total of 3385 subjects(mean age,51.29±11.42 years;57.1%male)were included in the study,and 89 among them were confirmed to have IM and presence of goblet cells via biopsy examination.The majority of these individuals were classified as short segment BE(n=85).The overall prevalence of BE was 2.6%.Multivariate analysis disclosed that old age[odds ratio(OR)=1.033;95%confidence interval(CI):1.012-1.055;P=0.002],male gender(OR=2.106;95%CI:1.145-3.872;P=0.017),ingestion of tea(OR=1.695;95%CI:1.043-2.754;P=0.033),and presence of hiatal hernia(OR=3.037;95%CI:1.765-5.225;P<0.001)were significant risk factors predicting BE.The independent risk factor for the presence of IM in ESEM lesions was old age alone(OR=1.029;95%CI:1.006-1.053;P=0.014).CONCLUSION Current prevalence of BE among the general population in Taiwan is 2.6%.Old age,male gender,ingestion of tea and hiatal hernia are significant risk factors for BE.展开更多
The primary purpose of this research was to give suitable irrigation program according to the growth period and water requirement.A cotton field experiment with mulched drip irrigation was conducted at the National Fi...The primary purpose of this research was to give suitable irrigation program according to the growth period and water requirement.A cotton field experiment with mulched drip irrigation was conducted at the National Field Observation and Research Station for Oasis Farmland Ecosystem in Aksu of Xinjiang in 2008.Water balance method was adopted to study the water requirement and water consumption law of cotton under mulched drip irrigation in Tarim Irrigated Area.Statistical analysis of experimental data of irrigation indicates that the relationship between yield of cotton and irrigation presents a quadratic parabola.We fit the model of cotton water production on the basis of field experimental data of cotton.And the analysis on water saving benefit of cotton under mulched drip irrigation was done.Results indicate that water requirements for the irrigated cotton are 543 mm in Tarim Irrigated Area.The water requirements of seedling stage is 252 mm,budding stage is 186 mm,bolling stage is 316 mm and wadding stage is 139 mm.the irrigation amount determines the spatial distribution of soil moisture and water consumption during cotton life cycle.However,water consumption at different growth stages was inconsistent with irrigation.Quantitatively,the water consumed by cotton decreases upon the increase of irrigation amount.From the perspective of water saving,the maximal water use efficiency can reach 3 091 m3/ha.But the highest cotton yield needs 3464 m3/ha irrigation water.In summary,compared to the conventional drip irrigation,a number of benefits in water saving and yield increase were observed when using plastic mulch.At the same amount of irrigation,the cotton yield with plastic mulch was 30.2% higher than conventional approaches,and the efficiency of water utilization increased by30.2%.While at the same yield level,29.3% water was saved by using plastic mulch,and the efficiency increased by 41.5%.展开更多
The beneficial effect of the alkali metals such as Na and K on the Cu(In.Ga)Se2 (CIGS) and Cu2ZnSn(S,Se)4 (CZTSSe) solar cells has been extensively investigated in the past two decades, however, in most of the...The beneficial effect of the alkali metals such as Na and K on the Cu(In.Ga)Se2 (CIGS) and Cu2ZnSn(S,Se)4 (CZTSSe) solar cells has been extensively investigated in the past two decades, however, in most of the studies the alkali metals were treated as dopants. Several recent studies have showed that the alkali metals may not only act as dopants but also form secondary phases in the absorber layer or on the surfaces of the films. Using the first-principles calculations, we screened out the most probable secondary phases of Na and K in CIGS and CZTSSe, and studied their electronic structures and optical properties. We found that all these alkali chalcogenide compounds have larger band gaps and lower VBM levels than CIGS and CZTSSe, because the existence of strong p-d coupling in CIS and CZTS pushes the valence band maximum (VBM) level up and reduces the band-gaps, while there is no such p-d coupling in these alkali chalcogenides. This band alignment repels the photo-generated holes from the secondary phases and prevents the electron-hole recombination. Moreover, the study on the optical properties of the secondary phases showed that the absorption coefficients of these alkali chalcogenides are much lower than those of CIGS and CZTSSe in the energy range of 0-3.4eV, which means that the alkali chalcogenides may not influence the absorption of solar light. Since the alkali metal dopants can passivate the grain boundaries and increase the hole carrier concentration, and meanwhile their related secondary phases have innocuous effect on the optical absorption and band alignment, we can understand why the alkali metal dopants can improve the CIGS and CZTSSe solar cell performance.展开更多
文摘We report the performances of a chalcopyrite Cu(In, Ga)Se<sub>2 </sub>CIGS-based thin-film solar cell with a newly employed high conductive n-Si layer. The data analysis was performed with the help of the 1D-Solar Cell Capacitance Simulator (1D-SCAPS) software program. The new device structure is based on the CIGS layer as the absorber layer, n-Si as the high conductive layer, i-In<sub>2</sub>S<sub>3</sub>, and i-ZnO as the buffer and window layers, respectively. The optimum CIGS bandgap was determined first and used to simulate and analyze the cell performance throughout the experiment. This analysis revealed that the absorber layer’s optimum bandgap value has to be 1.4 eV to achieve maximum efficiency of 22.57%. Subsequently, output solar cell parameters were analyzed as a function of CIGS layer thickness, defect density, and the operating temperature with an optimized n-Si layer. The newly modeled device has a p-CIGS/n-Si/In<sub>2</sub>S<sub>3</sub>/Al-ZnO structure. The main objective was to improve the overall cell performance while optimizing the thickness of absorber layers, defect density, bandgap, and operating temperature with the newly employed optimized n-Si layer. The increase of absorber layer thickness from 0.2 - 2 µm showed an upward trend in the cell’s performance, while the increase of defect density and operating temperature showed a downward trend in solar cell performance. This study illustrates that the proposed cell structure shows higher cell performances and can be fabricated on the lab-scale and industrial levels.
基金the 2020 National Social Science Fund Art Project“History of Chinese Film Thought(1905-1949)”(Project No.:20BC035).
文摘The“People’s Films,”when examined from the perspective of classical aesthetics,present a unique visual style that creates artistic conceptions through sparse filming and deliver a scenery-based ideology through background shots,contributing to the overall aesthetic taste dominated by plainness.Chinese national aesthetic tastes,distinguished by implicitness,symbolism,and ethereality,have the magical power to present charming conceptions via plain and simple scenes,thus endowing the“People’s Films”with natural,plain,and harmonious frames that are unique to China.Behind the silent and plain scenes are representations of personal cultivation and essential values cherished by the Chinese people,which are achieved via the momentary presence and entirety of scenes photographed in the films,delivering an internal transcendence of people’s consciousness.
文摘Sb<sub>2</sub>S<sub>3</sub> has gained tremendous research recently for thin film solar cell absorber material because of their easy synthesis, unique electrical and optical properties. The stoichiometry and composition of electroless Sb<sub>2</sub>S<sub>3</sub> thin films were analyzed using XPS depth profile studies. The surface layers were found nearly stoichiometric. On the other hand, the inner layer was rich in antimony composition making it more conductive electrically.
基金This work was supported by the Tianjin Municipal Education Commission,Horizontal subject(grant number 70304901).
文摘Cd_(1-x)Zn_(x)S thin films were deposited by chemical bath deposition(CBD)on the glass substrate to study the influence of cadmium sulfate concentration on the structural characteristics of the thin film.The SEM results show that the thin film surfaces under the cadmium sulfate concentration of 0.005 M exhibit better compactness and uniformity.The distribution diagrams of thin film elements illustrate the film growth rate changes on the trend of the increase,decrease,and increase with the increase of cadmium sulfate concentration.XRD studies exhibit the crystal structure of the film is the hexagonal phase,and there are obvious diffraction peaks and better crystallinity when the concentration is 0.005 M.Spectrophotometer test results demonstrate that the relationship between zinc content x and optical band gap value E_(g) can be expressed by the equation E_(g)(x)=0.59x^(2)+0.69x+2.43.Increasing the zinc content can increase the optical band gap,and the absorbance of the thin film can be improved by decreasing the cadmium sulfate concentration,however,all of them have good transmittance.At a concentration of 0.005 M,the thin film has good absorbance in the 300-800 nm range,80%transmittance,and band gap value of 3.24 eV,which is suitable for use as a buffer layer for solar cells.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61076063,61340051,and 61306120)the Natural Science Foundation of Fujian Province,China(Grant No.2014J05073)
文摘Ag- and Sn-doped In2S3 thin films were deposited on glass substrates using the thermal evaporation technique. The doping was realized by thermal diffusion. The influences of Ag and Sn impurities on the electrical, structural, morphological, and optical properties of the In2S3 films were investigated. In all deposited samples, the x-ray diffraction spectra revealed the formation of cubic In2S3 phase. A significant increase in the crystallite size was observed after Ag doping,while the doping of Sn slightly decreased the crystallite size. The x-ray photoelectron spectroscopy verified the diffusion of Ag and Sn into the In2S3 films after annealing. The optical study illustrated that Ag doping resulted in a reduction of the optical band gap while Sn doping led to a widening of the gap. Optical properties were investigated to determine the optical constants. Besides, it was found that the resistivity decreases significantly either after Ag or Sn incorporation. The study demonstrates that the Sn-doped In2S3 thin films are more suitable for buffer layer application in solar cells than the Ag-doped In2S3 thin films.
基金supports from National Natural Science Foundation of China (Nos.50775183 and 50805118)Research Fund for Doctoral Programof higher Education (N6CJ0001)National High Technical Research and Development Programme of China (No.2009AA04Z418)
文摘The flat cylindrical indentation tests with different sizes of punch radius were investigated using finite element method (FEM) aimed to reveal the effect of punch size on the indentation behavior of the film/substrate system. Based on the FEM results analysis, two methods was proposed to separate film's reduced Young's modulus from a film/substrate system. The first method was based on a new weight function that quantifies film's and substrate's contributions to the overall mechanical properties of the film/substrate system in the flat cylindrical indentation test. The second method, a numerical approach, including fitting and extrapolation procedures was put forward. Both of the results from the two methods showed a reasonable agreement with the one input FE model. At last, the effect of maximum indentation depth and the surface micro-roughness of the thin film on the reduced Young's modulus of the film/substrate system were discussed. The methods proposed in the present study provide some new conceptions on evaluating other properties of thin films, e.g. creep, for which a flat-ended punch is also employed.
文摘The primary objective of this study is to apply the Evaluation Grid Method(EGM)and the continuous fuzzy Kano quality model to explore the cognitive preferences of Taiwan China residents regarding the beauty of Taiwan’s China landscape paintings.The aim is to contribute to the development of social and cultural art and promote the widespread appeal of art products.Through a literature review,consultations with aesthetic experts,and the application of Miryoku Engineering’s EGM,this paper consolidates the factors that contribute to the attractiveness of painting art products among Taiwan China residents,taking into account various aesthetic qualities.Simultaneously,the paper introduces the use of the triangular fuzzy golden ratio scale semantics,specifically the equal-ratio aesthetic scale semantics,as a replacement for the traditional subjective consciousness model.Departing from the traditional discrete Kano model that employs the mode as the standard for evaluating quality,this study applies triangular fuzzy numbers to the continuous Kano quality model to analyze the diverse preferences and evaluation standards of the public.The hope is that this research methodology will not only deepen Taiwan China residents’understanding and aesthetic literacy of painting art but also serve as a reference for the popularization of art products.
文摘The regeneration procedure of Q-state PbS particles in lead arachidate(PbAr)Langmuir-Blodgett films have been studied by means of UV-vis absorption, FT-IR spectra and quartz crystal microbalance(QCM) measurements.The results showed that the mole fraction of PbS particles in LB films was increased by immersing PbScontaining ArH LB films in a Pb ̄(2+) buffer solution,followed by being reexposed to H_2S gas.
文摘Copper sulfide thin films are deposited onto different substrates at room temperature using the thermal evaporation technique. X-ray diffraction spectra show that the film has an orthorhombicchalcocite (7-Cu2S) phase. The atomic force microscopy images indicate that the film exhibits nanoparticles with an average size of nearly 44 nm. Specrtophotometric measurements for the transmittance and reflectance are carried out at normal incidence in a spectral wavelength range of 450 nm-2500 nm. The refractive index, n, as well as the absorption index, k is calculated. Some dispersion parameters are determined. The analyses of el and e2 reveal several absorption peaks. The analysis of the spectral behavior of the absorption coefficient, c~, in the absorption region reveals direct and indirect allowed transitions. The dark electrical resistivity is studied as a function of film thickness and temperature. Tellier's model is adopted for determining the mean free path and bulk resistance.
文摘Nanocrystalline copper oxide (CuO) thin films were deposited onto glass substrates by a spin coating technique using an aqueous solution of copper acetate. These films were characterized for their structural, mor-phological, optoelectronic properties by means of X-ray diffraction (XRD) scanning electron microscopy (SEM), UVspectroscopy and four probe method. The CuO films are oriented along (1 1 1) plane with the monoclinic crystal structure. These films were utilized in H2S sensors. The dependence of the H2S response on the operating temperature, H2S concentration of CuO film (annealed at 700。C) was investigated. The CuO film showed selectivity for H2S. The maximum H2S response of 25.2 % for the CuO film at gas concentra-tion of 100 ppm at operating temperature 200oC was achieved.
文摘Thin films of ZnxCd1-xS have been prepared by electron beam evaporation of a mixture of ZnS & CdS powders. The films are deposited onto sodalime glass slides under similar conditions.The composition of the films is varied from CdS to ZnS (x=0 to 1). The films show a regular change in color from toner red to orange yellow as Zn concentration increases to maximum.These films are characterized for their optical, electricaI and structural properties. The bandgap value of ZnxCd1-xS films is found to vary linearIy from 2.20 eV to 3.44 eV with change in the x value from 0 to 1. The resistivity of these films is in the range of 171.0 Ωcm to 5.5× 106Ωcm for x=0~0.6. All the samples show cubic structure after annealing in air at 250℃ for 40 min.The lattice constant ao varies from 0.5884 nm to 0.54109 nm linearly.
文摘The structural and thermomechanical properties of starch-based plastic films reinforced with kaolin and metakaolin have been studied by various techniques (X-ray diffraction, IR-TF spectroscopy, scanning electron microscopy, tensile tests, and thermal resistance). The results obtained showed that kaolin, an inert material, prevents the starch from losing its granular structure and to solubilize during the heating, generating plastic films of low Young’s modulus (7 MPa). On the other hand, metakaolin, an amorphous and dehydroxylated material obtained after heating of kaolin at 700°C for 1 hour, substantially improves the thermomechanical properties of the plastic films. The Young’s modulus increases from 19 MPa to 25 MPa while the thermal resistance increases from 90°C to 120°C. This was attributed to good dispersion of the metakaolin in the polymer matrix after the loss of the granular structure of the starch during heating.
文摘In this study, In<sub>2</sub>S<sub>3</sub> thin films have been deposited on ITO and fluorine-tinoxide FTO coated glass substrates by single source vacuum thermal evaporation annealed in vacuum a 300°C - 400°C for 1 h. The samples structure was characterized by X-ray diffraction, revealing the quadratic structure of In<sub>2</sub>S<sub>3</sub> and the crystallinity depends on the temperature of annealing and nature of substrate. The various structural parameters, such as, crystalline size, dislocation density, strain and texture coefficient were calculated. The optical properties show that the refractive index dispersion data obeyed the single oscillator of the Wemple-DiDomenico model. By using this model, the dispersion parameters and the high-frequency dielectric constant were determined. The Hall Effect has been studied at room temperature. The Hall voltages, the Hall coefficient (RH) and mobility (μH) have been measured at different magnetic and electric fields. The films show n-type behavior irrespective of temperature and composition.
文摘Chemical bath deposition technique has been used to deposit Ni-doped Sb2S3 thin films onto glass substrate. Doping was carried out by adding 1, 3 and 5 wt% of Ni. Bath temperature was kept as 10℃ and films were annealed at 250℃ under vacuum. Polycrystalline nature of films with an orthorhombic phase was analyzed by X-ray diffraction technique. Scanning electron microscopy was used for morphological study which shows that grains are spherical. Optical measurements using transmittance data indicated that films have a direct band gap of 1.00 - 2.60 eV with an absorption coefficient of ~104 cm<sup>-1</sup> in visible range. The average value of electrical conductivity was calculated as 1.66, 1.11 and 1.06 (Ω·cm)<sup>-1</sup> for as-deposited films and 1.90, 2.08 and 1.15 (Ω·cm)<sup>-1</sup> for annealed films while refractive indices were found as 2.18 - 3.38 and 1.91 - 3.74 respectively. The obtained films can be used for solar cell applications due to their good absorbing properties like higher absorption coefficient and refractive index values.
文摘Cu x S thin films are implanted by low energy N + ion beam. The influences of the energy and dose of N + ion implantation on Cu x S films are investigated. The results show that the ratio of copper to sulfur is increased to some extent, the constituents of the film are turned to rich copper phase from rich sulfurous phase after ion beam irradiation. X-ray diffraction spectrum and optical transmission spectra of sample have confirmed the results.
文摘The influence of thermal treatment on the lux-ampere characteristics of polycrystalline films from the CdSe<sub>x</sub>S<sub>1-x</sub> solid solution obtained by the method of thermal evaporation in a vacuum has been investigated. It is shown that at low illumination intensities L μ of electrons increases with a power law μ ~ L<sup>γ</sup>, first with the exponent γ > 1, then with γ ≈ 0.5, and their concentration n almost does not change. Starting from the intensity L > 12 - 15 lx, the electron concentration increases strongly n ~ L<sup>β</sup> from β ≈ 3.0, and the parameters n and μ reach relatively high values ~(10<sup>15</sup> - 10<sup>16</sup>) sm<sup>-3</sup> and ~(150 - 200) sm<sup>2</sup>/V·s, however further, at L > 50 lx, a weak dependence of n(L) and μ(L) with β, γ < 1.0 is found. The obtained experimental results are interpreted on the basis of a model of a semiconductor film with intergranular potential barriers when the concentration and barrier mechanisms of photoconductivity operate simultaneously.
基金Supported by the In-Hospital Research Project Funding of Kaohsiung Veterans General Hospital,No.VGHKS107-040
文摘BACKGROUND Barrett’s esophagus(BE)is a pre-malignant condition associated with the development of esophageal adenocarcinoma.The prevalence of BE in the general populations of Asian countries ranges from 0.06%to 1%.However,with lifestyle changes in Asian countries and adoption of western customs,the prevalence of BE might have increased.AIM To determine the current prevalence of BE in Taiwan,and to investigate risk factors predicting the presence of BE.METHODS This retrospective study was conducted at the Health Evaluation Center of Kaohsiung Veterans General Hospital in Taiwan.Between January 2015 and December 2015,3385 subjects undergoing routine esophagogastroduodenoscopy examinations as part of a health check-up at the Health Evaluation Center were included.Patient characteristics and endoscopic findings were carefully reviewed.Lesions with endoscopic findings consistent with BE awaiting histological evaluation were judged as endoscopically suspected esophageal metaplasia(ESEM).BE was defined based on extension of the columnar epithelium≥1 cm above the gastroesophageal junction and was confirmed based on the presence of specialized intestinal metaplasia(IM)in the metaplastic esophageal epithelium.Clinical factors of subjects with BE and subjects without BE were compared,and the risk factors predicting BE were analyzed.RESULTS A total of 3385 subjects(mean age,51.29±11.42 years;57.1%male)were included in the study,and 89 among them were confirmed to have IM and presence of goblet cells via biopsy examination.The majority of these individuals were classified as short segment BE(n=85).The overall prevalence of BE was 2.6%.Multivariate analysis disclosed that old age[odds ratio(OR)=1.033;95%confidence interval(CI):1.012-1.055;P=0.002],male gender(OR=2.106;95%CI:1.145-3.872;P=0.017),ingestion of tea(OR=1.695;95%CI:1.043-2.754;P=0.033),and presence of hiatal hernia(OR=3.037;95%CI:1.765-5.225;P<0.001)were significant risk factors predicting BE.The independent risk factor for the presence of IM in ESEM lesions was old age alone(OR=1.029;95%CI:1.006-1.053;P=0.014).CONCLUSION Current prevalence of BE among the general population in Taiwan is 2.6%.Old age,male gender,ingestion of tea and hiatal hernia are significant risk factors for BE.
基金Supported by 973 Project(2009CB421302)Innovation Project of Chinese Academy of Sciences(KZCX2-YW-127)Youth Science Foundation of China(41401025)
文摘The primary purpose of this research was to give suitable irrigation program according to the growth period and water requirement.A cotton field experiment with mulched drip irrigation was conducted at the National Field Observation and Research Station for Oasis Farmland Ecosystem in Aksu of Xinjiang in 2008.Water balance method was adopted to study the water requirement and water consumption law of cotton under mulched drip irrigation in Tarim Irrigated Area.Statistical analysis of experimental data of irrigation indicates that the relationship between yield of cotton and irrigation presents a quadratic parabola.We fit the model of cotton water production on the basis of field experimental data of cotton.And the analysis on water saving benefit of cotton under mulched drip irrigation was done.Results indicate that water requirements for the irrigated cotton are 543 mm in Tarim Irrigated Area.The water requirements of seedling stage is 252 mm,budding stage is 186 mm,bolling stage is 316 mm and wadding stage is 139 mm.the irrigation amount determines the spatial distribution of soil moisture and water consumption during cotton life cycle.However,water consumption at different growth stages was inconsistent with irrigation.Quantitatively,the water consumed by cotton decreases upon the increase of irrigation amount.From the perspective of water saving,the maximal water use efficiency can reach 3 091 m3/ha.But the highest cotton yield needs 3464 m3/ha irrigation water.In summary,compared to the conventional drip irrigation,a number of benefits in water saving and yield increase were observed when using plastic mulch.At the same amount of irrigation,the cotton yield with plastic mulch was 30.2% higher than conventional approaches,and the efficiency of water utilization increased by30.2%.While at the same yield level,29.3% water was saved by using plastic mulch,and the efficiency increased by 41.5%.
基金supported by the National Natural Science Foundation of China(NSFC)under grant nos.61574059 and 61722402the National Key Research and Development Program of China(2016YFB0700700)+1 种基金Shu-Guang program(15SG20)CC of ECNU
文摘The beneficial effect of the alkali metals such as Na and K on the Cu(In.Ga)Se2 (CIGS) and Cu2ZnSn(S,Se)4 (CZTSSe) solar cells has been extensively investigated in the past two decades, however, in most of the studies the alkali metals were treated as dopants. Several recent studies have showed that the alkali metals may not only act as dopants but also form secondary phases in the absorber layer or on the surfaces of the films. Using the first-principles calculations, we screened out the most probable secondary phases of Na and K in CIGS and CZTSSe, and studied their electronic structures and optical properties. We found that all these alkali chalcogenide compounds have larger band gaps and lower VBM levels than CIGS and CZTSSe, because the existence of strong p-d coupling in CIS and CZTS pushes the valence band maximum (VBM) level up and reduces the band-gaps, while there is no such p-d coupling in these alkali chalcogenides. This band alignment repels the photo-generated holes from the secondary phases and prevents the electron-hole recombination. Moreover, the study on the optical properties of the secondary phases showed that the absorption coefficients of these alkali chalcogenides are much lower than those of CIGS and CZTSSe in the energy range of 0-3.4eV, which means that the alkali chalcogenides may not influence the absorption of solar light. Since the alkali metal dopants can passivate the grain boundaries and increase the hole carrier concentration, and meanwhile their related secondary phases have innocuous effect on the optical absorption and band alignment, we can understand why the alkali metal dopants can improve the CIGS and CZTSSe solar cell performance.