Low resistivity and highly transparent ITO conducting films for solar cell applications were fabricated at low temperature by r.f. magnetron sputtering. ITO films were deposited on glass and silicon substrate. Electri...Low resistivity and highly transparent ITO conducting films for solar cell applications were fabricated at low temperature by r.f. magnetron sputtering. ITO films were deposited on glass and silicon substrate. Electrical, optical, structural and morphological properties of the ITO films were investigated in terms of the preparation conditions. The annealing treatment has improved the properties of the ITO films at different degree. The maximum transmittance of the obtained ITO films in the visible range is over 92%, and the low resistivity for the ITO films are about 3.85×10-4 Ω·cm at 80 ℃, 80 W after annealing.展开更多
Aluminum-doped zinc oxide (AZO) thin films were deposited on sapphire (002) and glass substrates by two different sputtering techniques radio frequency magnetron cosputtering of AZO and ZnO targets and sputtering of a...Aluminum-doped zinc oxide (AZO) thin films were deposited on sapphire (002) and glass substrates by two different sputtering techniques radio frequency magnetron cosputtering of AZO and ZnO targets and sputtering of an AZO target. The dependence of the photoluminescence (PL) and transmittance properties of the AZO films deposited by cosputtering and sputtering on the AZO/ZnO target power ratio, R and the O2/Ar flow ratio, r were investigated, respectively. Only a deep level emission peak appears in the PL spectra of cosputtered AZO films whereas both UV emission and deep level emission peaks are observed in the PL spectra of sputtered AZO films. The absorption edges in the transmittance spectra of the AZO films shift to the lower wavelength region as R and r increase. Effects of crystallinity, surface roughness, PL on the transmittance of the AZO films were also explained using the X-ray diffraction (XRD), atomic force microscopy (AFM), and PL analysis results.展开更多
GaN nanorods have successfully been synthesized on Si(111) substrates via ammoniating ZnO/Ga2O3 films at 950 degrees C. Ga2O3 thin films and ZnO middle layers were deposited in turn on Si(111) substrates by r.f. magne...GaN nanorods have successfully been synthesized on Si(111) substrates via ammoniating ZnO/Ga2O3 films at 950 degrees C. Ga2O3 thin films and ZnO middle layers were deposited in turn on Si(111) substrates by r.f. magnetron sputtering system. ZnO volatilized at 950 degrees C in the ammonia ambience and Ga2O3 reacted to NH3 to fabricate GaN nanorods in the later ammoniating process. The volatilization of ZnO layers played an important role in the fabrication. The structure and composition of the GaN nanorods were studied by X-ray diffraction (XRD) and Fourier transform infrared spectrophotometer (FTIR). The morphology of GaN nanorods was investigated using scanning electron microscopy (SEM) and transmission electronic microscope (TEM). The analyses of measured results revealed that GaN nanorods with hexagonal wurtzite structure were prepared by this method.展开更多
Hexagonal GaN films were prepared by nitriding Ga_2O_3 films with flowingammonia. Ga_2O_3 films were deposited on Ga-diffused Si (111) substrates by radio frequency (r.f.)magnetron sputtering. This paper have investig...Hexagonal GaN films were prepared by nitriding Ga_2O_3 films with flowingammonia. Ga_2O_3 films were deposited on Ga-diffused Si (111) substrates by radio frequency (r.f.)magnetron sputtering. This paper have investigated the change of structural properties of GaN filmsnitrided in NH_3 atmosphere at the temperatures of 850, 900, and 950 deg C for 15 min and nitridedat the temperature of 900 deg C for 10, 15, and 20 min, respectively. X-ray diffraction (XRD),scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectronspectroscopy (XPS) were used to analyze the structure, surface morphology and composition ofsynthesized samples. The results reveal that the as-grown films are polycrystalline GaN withhexagonal wurtzite structure and GaN films with the highest crystal quality can be obtained whennitrided at 900 deg C for 15 min.展开更多
Hexagonal GaN micro-ribbons were synthesized through nitriding Ga2O3 films under flowing ammonia. Ga2O3 films were deposited on the Ga-diffused Si (111) substrates by radio frequency (r.f.) magnetron sputtering. X-ray...Hexagonal GaN micro-ribbons were synthesized through nitriding Ga2O3 films under flowing ammonia. Ga2O3 films were deposited on the Ga-diffused Si (111) substrates by radio frequency (r.f.) magnetron sputtering. X-ray diffraction (XRD), scanning electron microscopy (SEM), selected area electron diffraction (SAED); X-ray photo electronic spectrometer (XPS) and photoluminescence (PL) spectroscopy were used to characterize the structure, surface morphology, composition and optical property of the synthesized samples. SEM images show that GaN micro-ribbons with 100-300rim in diameter are randomly distributed on the uniform films. XRD, XPS and SAED analysis suggest the micro-ribbons are polycrystalline GaN with hexagonal structure and preferentially grow in the [001] direction. The PL spectrum has a remarkable blue shift compared with the reported values of bulk GaN, which might be ascribed to quantum confinement effects.展开更多
We have developed a novel thermoelectric gas sensors based on bismuth telluride thin films.These sensors were employed for sensing different concentrations of H_2 gas.Radio frequency (R.F.) magnetron sputtering was em...We have developed a novel thermoelectric gas sensors based on bismuth telluride thin films.These sensors were employed for sensing different concentrations of H_2 gas.Radio frequency (R.F.) magnetron sputtering was employed to deposit the bismuth telluride (Bi_2Te_3) thin films.The morphology of such thin films was investigated and responses of the thermoelectric devices to H_2 were studied.展开更多
Fe/Ti multilayers with different modulation wavelengths (Lambda) prepared by r.f. sputtering has been investigated by using cross sectional transmission electron microscopy (XTEM). It was observed that the columnar st...Fe/Ti multilayers with different modulation wavelengths (Lambda) prepared by r.f. sputtering has been investigated by using cross sectional transmission electron microscopy (XTEM). It was observed that the columnar structure, interface morphology, and metastable phase presented at the interface of the multilayer system strongly depend on the bilayer thickness (Lambda). For high period multilayers, the waviness wavelength of interfaces is about two times broader than the column diameter. For a sample with Lambda =30 nm, its column width and waviness wavelength was about 80, and 190 nm, respectively. Both of them decreased with the reduction of Lambda, so as to nearly equal values of column diameter and waviness wavelength were obtained. The Fe and Ti grains of both 30 nm and 6 nm multilayers are polycrystalline, and have a textured structure. In short bilayer thickness (Lambda =6 nm), the intermetallic compound Fe2Ti was presented at the interfaces due to solid state reaction; for Lambda =2 nm, amorphous phase Ti-rich layer was formed at the interfaces, resulting in a sharp interface multilayer structure.展开更多
In this paper, three kinds of textured ZnO thin-films (the first kind has the textured structure with both columnar and polygon, the second posses pyramid-like textured structure only, and the third has the textured s...In this paper, three kinds of textured ZnO thin-films (the first kind has the textured structure with both columnar and polygon, the second posses pyramid-like textured structure only, and the third has the textured structure with both crater-like and pyramid-like), were prepared by three kinds of methods, and the application of these ZnO thin-films as a front electrode in solar cell was studied, respectively. In the first method with negative bias voltage and appropriate sputtering parameters, the textured structure with columnar and polygon on the surface of ZnO thin-film are both existence for the sample prepared by direct magnetron sputtering. Using as a front electrode in solar cell, the photoelectric conversion efficiency Eff of 7.00% was obtained. The second method is that by sputtering on the ZnO:Al self-supporting substrate, and the distribution of pyramid-like was gained. Moreover, the higher (8.25%) photoelectric conversion efficiency of solar cell was got. The last method is that by acid-etching the as-deposited ZnO thin-film which possesses mainly both columnar and polygon structure, and the textured ZnO thin-film with both crater-like and pyramid-like structure was obtained, and the photoelectric conversion efficiency of solar cell is 7.10% when using it as front electrode. These results show that the textured ZnO thin-film prepared on self-supporting substrate is more suitable for using as a front electrode in amorphous silicon cells.展开更多
基金This project was financially supported by the Natural Science Foundation of Hebei Province, China. (No. F2005000073).
文摘Low resistivity and highly transparent ITO conducting films for solar cell applications were fabricated at low temperature by r.f. magnetron sputtering. ITO films were deposited on glass and silicon substrate. Electrical, optical, structural and morphological properties of the ITO films were investigated in terms of the preparation conditions. The annealing treatment has improved the properties of the ITO films at different degree. The maximum transmittance of the obtained ITO films in the visible range is over 92%, and the low resistivity for the ITO films are about 3.85×10-4 Ω·cm at 80 ℃, 80 W after annealing.
文摘Aluminum-doped zinc oxide (AZO) thin films were deposited on sapphire (002) and glass substrates by two different sputtering techniques radio frequency magnetron cosputtering of AZO and ZnO targets and sputtering of an AZO target. The dependence of the photoluminescence (PL) and transmittance properties of the AZO films deposited by cosputtering and sputtering on the AZO/ZnO target power ratio, R and the O2/Ar flow ratio, r were investigated, respectively. Only a deep level emission peak appears in the PL spectra of cosputtered AZO films whereas both UV emission and deep level emission peaks are observed in the PL spectra of sputtered AZO films. The absorption edges in the transmittance spectra of the AZO films shift to the lower wavelength region as R and r increase. Effects of crystallinity, surface roughness, PL on the transmittance of the AZO films were also explained using the X-ray diffraction (XRD), atomic force microscopy (AFM), and PL analysis results.
基金This work was financially supported by the Key Research Program of National Natural Science Foundation of China (No. 90301002 and No. 90201025).
文摘GaN nanorods have successfully been synthesized on Si(111) substrates via ammoniating ZnO/Ga2O3 films at 950 degrees C. Ga2O3 thin films and ZnO middle layers were deposited in turn on Si(111) substrates by r.f. magnetron sputtering system. ZnO volatilized at 950 degrees C in the ammonia ambience and Ga2O3 reacted to NH3 to fabricate GaN nanorods in the later ammoniating process. The volatilization of ZnO layers played an important role in the fabrication. The structure and composition of the GaN nanorods were studied by X-ray diffraction (XRD) and Fourier transform infrared spectrophotometer (FTIR). The morphology of GaN nanorods was investigated using scanning electron microscopy (SEM) and transmission electronic microscope (TEM). The analyses of measured results revealed that GaN nanorods with hexagonal wurtzite structure were prepared by this method.
基金This work was financially supported by the Science Research Foundation of Shandong Jiaotong University (No. Z200503) and the National Natural Science Foundation of China (No. 90301002).
文摘Hexagonal GaN films were prepared by nitriding Ga_2O_3 films with flowingammonia. Ga_2O_3 films were deposited on Ga-diffused Si (111) substrates by radio frequency (r.f.)magnetron sputtering. This paper have investigated the change of structural properties of GaN filmsnitrided in NH_3 atmosphere at the temperatures of 850, 900, and 950 deg C for 15 min and nitridedat the temperature of 900 deg C for 10, 15, and 20 min, respectively. X-ray diffraction (XRD),scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectronspectroscopy (XPS) were used to analyze the structure, surface morphology and composition ofsynthesized samples. The results reveal that the as-grown films are polycrystalline GaN withhexagonal wurtzite structure and GaN films with the highest crystal quality can be obtained whennitrided at 900 deg C for 15 min.
文摘Hexagonal GaN micro-ribbons were synthesized through nitriding Ga2O3 films under flowing ammonia. Ga2O3 films were deposited on the Ga-diffused Si (111) substrates by radio frequency (r.f.) magnetron sputtering. X-ray diffraction (XRD), scanning electron microscopy (SEM), selected area electron diffraction (SAED); X-ray photo electronic spectrometer (XPS) and photoluminescence (PL) spectroscopy were used to characterize the structure, surface morphology, composition and optical property of the synthesized samples. SEM images show that GaN micro-ribbons with 100-300rim in diameter are randomly distributed on the uniform films. XRD, XPS and SAED analysis suggest the micro-ribbons are polycrystalline GaN with hexagonal structure and preferentially grow in the [001] direction. The PL spectrum has a remarkable blue shift compared with the reported values of bulk GaN, which might be ascribed to quantum confinement effects.
文摘We have developed a novel thermoelectric gas sensors based on bismuth telluride thin films.These sensors were employed for sensing different concentrations of H_2 gas.Radio frequency (R.F.) magnetron sputtering was employed to deposit the bismuth telluride (Bi_2Te_3) thin films.The morphology of such thin films was investigated and responses of the thermoelectric devices to H_2 were studied.
基金Financial support from National Natural Science Foundation of China and the Ministry of Science&Technology of China(Grant No.(1999064505)is acknowledged.
文摘Fe/Ti multilayers with different modulation wavelengths (Lambda) prepared by r.f. sputtering has been investigated by using cross sectional transmission electron microscopy (XTEM). It was observed that the columnar structure, interface morphology, and metastable phase presented at the interface of the multilayer system strongly depend on the bilayer thickness (Lambda). For high period multilayers, the waviness wavelength of interfaces is about two times broader than the column diameter. For a sample with Lambda =30 nm, its column width and waviness wavelength was about 80, and 190 nm, respectively. Both of them decreased with the reduction of Lambda, so as to nearly equal values of column diameter and waviness wavelength were obtained. The Fe and Ti grains of both 30 nm and 6 nm multilayers are polycrystalline, and have a textured structure. In short bilayer thickness (Lambda =6 nm), the intermetallic compound Fe2Ti was presented at the interfaces due to solid state reaction; for Lambda =2 nm, amorphous phase Ti-rich layer was formed at the interfaces, resulting in a sharp interface multilayer structure.
文摘In this paper, three kinds of textured ZnO thin-films (the first kind has the textured structure with both columnar and polygon, the second posses pyramid-like textured structure only, and the third has the textured structure with both crater-like and pyramid-like), were prepared by three kinds of methods, and the application of these ZnO thin-films as a front electrode in solar cell was studied, respectively. In the first method with negative bias voltage and appropriate sputtering parameters, the textured structure with columnar and polygon on the surface of ZnO thin-film are both existence for the sample prepared by direct magnetron sputtering. Using as a front electrode in solar cell, the photoelectric conversion efficiency Eff of 7.00% was obtained. The second method is that by sputtering on the ZnO:Al self-supporting substrate, and the distribution of pyramid-like was gained. Moreover, the higher (8.25%) photoelectric conversion efficiency of solar cell was got. The last method is that by acid-etching the as-deposited ZnO thin-film which possesses mainly both columnar and polygon structure, and the textured ZnO thin-film with both crater-like and pyramid-like structure was obtained, and the photoelectric conversion efficiency of solar cell is 7.10% when using it as front electrode. These results show that the textured ZnO thin-film prepared on self-supporting substrate is more suitable for using as a front electrode in amorphous silicon cells.
