CdSe films are of great interest for use in thin film photoelectric devices. A simple chemical precipitation method is adopted for the first time to synthesise CdSe powder. Films on glass obtained at different substra...CdSe films are of great interest for use in thin film photoelectric devices. A simple chemical precipitation method is adopted for the first time to synthesise CdSe powder. Films on glass obtained at different substrate temperatures TS such as 300, 373, 423 and 473 K have been characterised by X-ray diffraction, optical absorption and Hall measurements.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 Be films were prepared by thermal evaporation at different sources to substrate distances（SSD） on glass substrates. The decrease of SSD from 90 mm to 50 mm caused the increase of substrate temperature and the ri...The Be films were prepared by thermal evaporation at different sources to substrate distances（SSD） on glass substrates. The decrease of SSD from 90 mm to 50 mm caused the increase of substrate temperature and the rising density of incident Be atoms, thus the properties of Be films greatly changed accordingly. The experimental results showed that the grain diameter in the Be films transited from below 100 nm to 300 nm, the film growth rate increased from 2.35 nm/min to 4.73 nm/min and the roughness increased from 7 nm to 49 nm. The performance study suggested that the friction coefficient of Be films increased from 0.13 to 0.27 and was related to the surface roughness and inner structure, the near-infrared reflectance of Be films increased from 40% to 85% with the increase of wavelength and concurrently decreased with the decrease of SSD, respectively. The performance study indicated that the Be film had the potential application in specific near-infrared reflectance optical system.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
文摘CdSe films are of great interest for use in thin film photoelectric devices. A simple chemical precipitation method is adopted for the first time to synthesise CdSe powder. Films on glass obtained at different substrate temperatures TS such as 300, 373, 423 and 473 K have been characterised by X-ray diffraction, optical absorption and Hall measurements.
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.
基金Funded by the Laboratory of Precision Manufacturing Technology,China Academy of Engineering Physics(No.ZZ15011)
文摘The Be films were prepared by thermal evaporation at different sources to substrate distances（SSD） on glass substrates. The decrease of SSD from 90 mm to 50 mm caused the increase of substrate temperature and the rising density of incident Be atoms, thus the properties of Be films greatly changed accordingly. The experimental results showed that the grain diameter in the Be films transited from below 100 nm to 300 nm, the film growth rate increased from 2.35 nm/min to 4.73 nm/min and the roughness increased from 7 nm to 49 nm. The performance study suggested that the friction coefficient of Be films increased from 0.13 to 0.27 and was related to the surface roughness and inner structure, the near-infrared reflectance of Be films increased from 40% to 85% with the increase of wavelength and concurrently decreased with the decrease of SSD, respectively. The performance study indicated that the Be film had the potential application in specific near-infrared reflectance optical system.
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.
