Al-doped ZnO(AZO)/Cu bi-layer films are deposited by dc magnetron sputtering on polycarbonate substrates at room temperature.The structural,electrical and optical properties of the films are investigated at various sp...Al-doped ZnO(AZO)/Cu bi-layer films are deposited by dc magnetron sputtering on polycarbonate substrates at room temperature.The structural,electrical and optical properties of the films are investigated at various sputtering powers of the Cu layer.The AZO/Cu bi-layer film deposited at a moderate sputtering power of 180 W for the Cu layer displayed the highest figure of merit of 3.47×10^(−3)Ω^(-1),with a low sheet resistance of 12.38Ω/sq,an acceptable visible transmittance of 73%,and a high near-infrared reflectance of about 50%.展开更多
The epitaxial growth of a high-quality silicon layer on double-layer porous silicon by ultra-high vacuum/chemical vapour deposition has been reported. The two-step anodization process results in a double-layer porous ...The epitaxial growth of a high-quality silicon layer on double-layer porous silicon by ultra-high vacuum/chemical vapour deposition has been reported. The two-step anodization process results in a double-layer porous silicon structure with a different porosity. This double-layer porous silicon structure and an extended low-temperature annealing in a vacuum system was found to be helpful in subsequent silicon epitaxial growth. X-ray diffraction,cross-sectional transmission electron microscopy and spreading resistance testing were used in this work to study the properties of epitaxial silicon layers grown on the double-layer porous silicon. The results show that the epitaxial silicon layer is of good crystallinity and the same orientation with the silicon substrate and the porous silicon layer.展开更多
High quality Si_(1-x-y)Ge_(x)C_(y) alloy with 2.2%C is grown at a relatively high temperature(760℃)on Si(100)using ultra-high vacuum/chemical vapor deposition(UHV/CVD)system.The samples are investigated with high res...High quality Si_(1-x-y)Ge_(x)C_(y) alloy with 2.2%C is grown at a relatively high temperature(760℃)on Si(100)using ultra-high vacuum/chemical vapor deposition(UHV/CVD)system.The samples are investigated with high resolution cross-sectioned transmission electron microscope and x-ray diffraction.Compared with Si_(1-x)Ge_(x) alloys,Si_(1-x-y)Ge_(x)C_(y) alloys with small amounts of Chave much less strain and larger critical layer thickness.The quality of interface is edso improved.Relatively flat growing profiles of the film are confirmed by secondary ion mass spectroscopy.Fourier transform infrared spectroscopy is also used to testify that the carbon atoms are on the substitutional sites.It is proved that the UHV/CVD system is an efficient method of growing Si_(1-x-y)Ge_(x)C_(y) alloys.展开更多
GaN epilayer grown on Si(111)substrate by a novel vacuum reaction method rather than metal organic chemical vapor deposition or molecule beam epitaxy is reported.Scanning electron micrograph shows that surface of GaN ...GaN epilayer grown on Si(111)substrate by a novel vacuum reaction method rather than metal organic chemical vapor deposition or molecule beam epitaxy is reported.Scanning electron micrograph shows that surface of GaN film is flat and crack-free.A pronounced GaN(0002)peak appears in the x-ray diffraction pattern.The full width at half-maximum(FWHM)of the double-crystal x-ray rocking curve for(0002)diffraction from the GaN epilayer is 30arcmin.The photoluminescence spectrum shows that the GaN epilayer emits light at the wavelength of 365nm with an FWHM of 8nm(74.6meV).展开更多
A SiGe/Si epilayer with a linear-step-graded buffer was grown by ultrahigh vacuum chemical vapor deposition technique at a relatively high growth temperature(780℃)and a relatively high growth rate.Almost linear Ge co...A SiGe/Si epilayer with a linear-step-graded buffer was grown by ultrahigh vacuum chemical vapor deposition technique at a relatively high growth temperature(780℃)and a relatively high growth rate.Almost linear Ge content variation was realized in the buffer layer due to the Ge segregation to the growing surface during epitaxial growth.Double crystal x-ray diffraction and Raman spectroscopy show that the upper layer is fully relaxed.However,the measured results show that the density of dislocation in the composition graded structure is much lower than that in single-step epilayer structures.展开更多
We report the identification of a donor band and the correlation between n-type conductivity and the green emission in ZnO nanowires.Temperature-dependent photoluminescence is used to investigate nominally undoped ZnO...We report the identification of a donor band and the correlation between n-type conductivity and the green emission in ZnO nanowires.Temperature-dependent photoluminescence is used to investigate nominally undoped ZnO nanowires with high n-type conductivity.Within the whole temperature range,a dominant free-to-bound transition with a donor band of about 150meV below the conduction band minimum is observed.The nanowires show very strong green emission,which is quenched with activation energy of about 220 meV.The correlation between the high n-type conductivity and the strong green emission is discussed in detail,and we suggest that they may have different origins.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 51002131the Fundamental Research Funds for the Central Universities under Grant No 2011FZA4009.
文摘Al-doped ZnO(AZO)/Cu bi-layer films are deposited by dc magnetron sputtering on polycarbonate substrates at room temperature.The structural,electrical and optical properties of the films are investigated at various sputtering powers of the Cu layer.The AZO/Cu bi-layer film deposited at a moderate sputtering power of 180 W for the Cu layer displayed the highest figure of merit of 3.47×10^(−3)Ω^(-1),with a low sheet resistance of 12.38Ω/sq,an acceptable visible transmittance of 73%,and a high near-infrared reflectance of about 50%.
基金Supported by the National Natural Science Foundation of China under Grant No.69876007。
文摘The epitaxial growth of a high-quality silicon layer on double-layer porous silicon by ultra-high vacuum/chemical vapour deposition has been reported. The two-step anodization process results in a double-layer porous silicon structure with a different porosity. This double-layer porous silicon structure and an extended low-temperature annealing in a vacuum system was found to be helpful in subsequent silicon epitaxial growth. X-ray diffraction,cross-sectional transmission electron microscopy and spreading resistance testing were used in this work to study the properties of epitaxial silicon layers grown on the double-layer porous silicon. The results show that the epitaxial silicon layer is of good crystallinity and the same orientation with the silicon substrate and the porous silicon layer.
基金Supported by the National Natural Science Foundation of China under Grant No.69686002.
文摘High quality Si_(1-x-y)Ge_(x)C_(y) alloy with 2.2%C is grown at a relatively high temperature(760℃)on Si(100)using ultra-high vacuum/chemical vapor deposition(UHV/CVD)system.The samples are investigated with high resolution cross-sectioned transmission electron microscope and x-ray diffraction.Compared with Si_(1-x)Ge_(x) alloys,Si_(1-x-y)Ge_(x)C_(y) alloys with small amounts of Chave much less strain and larger critical layer thickness.The quality of interface is edso improved.Relatively flat growing profiles of the film are confirmed by secondary ion mass spectroscopy.Fourier transform infrared spectroscopy is also used to testify that the carbon atoms are on the substitutional sites.It is proved that the UHV/CVD system is an efficient method of growing Si_(1-x-y)Ge_(x)C_(y) alloys.
基金Supported by thw Talents Across the Century of Education Ministry of Chinathe National Natural Science Foundation of China under Grant No.69890230.
文摘GaN epilayer grown on Si(111)substrate by a novel vacuum reaction method rather than metal organic chemical vapor deposition or molecule beam epitaxy is reported.Scanning electron micrograph shows that surface of GaN film is flat and crack-free.A pronounced GaN(0002)peak appears in the x-ray diffraction pattern.The full width at half-maximum(FWHM)of the double-crystal x-ray rocking curve for(0002)diffraction from the GaN epilayer is 30arcmin.The photoluminescence spectrum shows that the GaN epilayer emits light at the wavelength of 365nm with an FWHM of 8nm(74.6meV).
基金Supported by the National Natural Science Foundation of China under Grant No.69686002the‘Talents Across the Century’of Education Ministry of Chinathe Natural Science Fund of Zhejiang Province.
文摘A SiGe/Si epilayer with a linear-step-graded buffer was grown by ultrahigh vacuum chemical vapor deposition technique at a relatively high growth temperature(780℃)and a relatively high growth rate.Almost linear Ge content variation was realized in the buffer layer due to the Ge segregation to the growing surface during epitaxial growth.Double crystal x-ray diffraction and Raman spectroscopy show that the upper layer is fully relaxed.However,the measured results show that the density of dislocation in the composition graded structure is much lower than that in single-step epilayer structures.
基金Supported by the Research Program in Baoji University of Arts and Sciences under Grant No ZK072the Natural Science Foundation of China under Grant No 60806003+2 种基金the Doctoral Fund of Ministry of Education of China under Grant No 20070335010the Priority Research Centers Program through the National Research Foundation of Korea(NRF)Funded by the Ministry of Education,Science and Technology(2009-0094049,313-2007-2-C00266)Excellence Research Program in Ajou University.
文摘We report the identification of a donor band and the correlation between n-type conductivity and the green emission in ZnO nanowires.Temperature-dependent photoluminescence is used to investigate nominally undoped ZnO nanowires with high n-type conductivity.Within the whole temperature range,a dominant free-to-bound transition with a donor band of about 150meV below the conduction band minimum is observed.The nanowires show very strong green emission,which is quenched with activation energy of about 220 meV.The correlation between the high n-type conductivity and the strong green emission is discussed in detail,and we suggest that they may have different origins.
