Zinc sulphide(ZnS) thin films have grown on glass and Si substrates by reactive cathodic radio frequency(RF) sputtering. The RF power was varied in the range of 100 to 250 W, while the deposition time is set at75 min....Zinc sulphide(ZnS) thin films have grown on glass and Si substrates by reactive cathodic radio frequency(RF) sputtering. The RF power was varied in the range of 100 to 250 W, while the deposition time is set at75 min. The optical, structural, and morphological properties of these thin films have been studied. The optical properties(mainly thickness, refractive index,absorption coefficient, and optical band gap) were investigated by optical transmittance measurements in the wavelength range of ultraviolet-visible-near infrared spectroscopy and spectroscopy infrared with Fourier transform. Fourier(FT-IR) and XRD analysis indicated that all sputtering ZnS films had a single-phase with a preferred orientation along the(111) plane of the zinc sphalerite phase(ZB). The crystallite size ranged from 11.5 to 48.5 nm with RF power getting a maximum of 200 W. UV-visible measurements exhibited that the ZnS film had more than 80% transmission in the visible wavelength region. In addition, it has been observed that the band gap energy of ZnS films is decreased slightly from 3.52 to 3.29 eV, and as the RF power is increased, the film thickness increases with the speed of deposit growth. Scanning electron microscopy observations revealed the types of smooth-surfaced films. The measurements(FT-IR) revealed at wave number1118 and 465.02 cmabsorption bands corresponding to the symmetrical and asymmetric vibration of the Zn-S stretching mode. X-ray reflectometry measurements of ZnS films have shown that the density of the films is(3.9 g/cm~3) close to that of solid ZnS.展开更多
Over the past few years, Cu-based materials have been intensively studied focusing on their structural and thermoelectric properties. In this work, copper sulphide powders were synthesized by the sol-gel method. The c...Over the past few years, Cu-based materials have been intensively studied focusing on their structural and thermoelectric properties. In this work, copper sulphide powders were synthesized by the sol-gel method. The chemical composition and the morphological properties of the obtained samples were analyzed by X-ray diffraction, differential thermal analysis, and scanning electron microscopy. It is shown that the decomposition from one phase to another can be obtained by annealing. The electrical resistivity and the crystallite size were found to be strongly affected by the phase transition. Thermoelectric analyses showed that the digenite phase exhibits the highest power factor at room temperature. The Seebeck coefficient of the compound Cu1.8S shows a pronounced peak at the γ-β transition temperature. This behavior was statistically explained in terms of a dramatic increase in the disorder in the atoms-carriers ensemble.展开更多
文摘Zinc sulphide(ZnS) thin films have grown on glass and Si substrates by reactive cathodic radio frequency(RF) sputtering. The RF power was varied in the range of 100 to 250 W, while the deposition time is set at75 min. The optical, structural, and morphological properties of these thin films have been studied. The optical properties(mainly thickness, refractive index,absorption coefficient, and optical band gap) were investigated by optical transmittance measurements in the wavelength range of ultraviolet-visible-near infrared spectroscopy and spectroscopy infrared with Fourier transform. Fourier(FT-IR) and XRD analysis indicated that all sputtering ZnS films had a single-phase with a preferred orientation along the(111) plane of the zinc sphalerite phase(ZB). The crystallite size ranged from 11.5 to 48.5 nm with RF power getting a maximum of 200 W. UV-visible measurements exhibited that the ZnS film had more than 80% transmission in the visible wavelength region. In addition, it has been observed that the band gap energy of ZnS films is decreased slightly from 3.52 to 3.29 eV, and as the RF power is increased, the film thickness increases with the speed of deposit growth. Scanning electron microscopy observations revealed the types of smooth-surfaced films. The measurements(FT-IR) revealed at wave number1118 and 465.02 cmabsorption bands corresponding to the symmetrical and asymmetric vibration of the Zn-S stretching mode. X-ray reflectometry measurements of ZnS films have shown that the density of the films is(3.9 g/cm~3) close to that of solid ZnS.
文摘Over the past few years, Cu-based materials have been intensively studied focusing on their structural and thermoelectric properties. In this work, copper sulphide powders were synthesized by the sol-gel method. The chemical composition and the morphological properties of the obtained samples were analyzed by X-ray diffraction, differential thermal analysis, and scanning electron microscopy. It is shown that the decomposition from one phase to another can be obtained by annealing. The electrical resistivity and the crystallite size were found to be strongly affected by the phase transition. Thermoelectric analyses showed that the digenite phase exhibits the highest power factor at room temperature. The Seebeck coefficient of the compound Cu1.8S shows a pronounced peak at the γ-β transition temperature. This behavior was statistically explained in terms of a dramatic increase in the disorder in the atoms-carriers ensemble.
