Titanic acid nanotubes(H_(2)Ti_(2)O_(4)(OH)_(2))were surface-modified with cetyl alcohol through dehydration reaction because of existence of Ti–OH.The modified nanotubes were characterized by transmission electron m...Titanic acid nanotubes(H_(2)Ti_(2)O_(4)(OH)_(2))were surface-modified with cetyl alcohol through dehydration reaction because of existence of Ti–OH.The modified nanotubes were characterized by transmission electron microscopy(TEM),Fourier Transform Infrared(FT-IR)spectrometry and pho-toluminescence(PL)spectra.The results indicate that the modified nanotubes can be easily dis-persed into organic solvent such as chloroform and toluene in contrast with the unmodified nanotubes,which makes it easier to be assembled by LB technique.Moreover,the Ti-O-CH_(2)(CH_(2))_(14)CH_(3) on the surface of the nanotubes can hinder the adsorption of water and consequently the photoluminescence property of the nanotubes can be stabilized.Even though kept in humid condition or in air for a long time,the modified nanotubes also maintain the special photoluminescence property in the visible region.展开更多
Atomic Force Microscopy (AFM) mechanical lithography is a simple but significant method for nanofabrication. In this work, we used this method to construct nanos- tructures on Pt/Cu bilayer metal electrodes under ambi...Atomic Force Microscopy (AFM) mechanical lithography is a simple but significant method for nanofabrication. In this work, we used this method to construct nanos- tructures on Pt/Cu bilayer metal electrodes under ambient conditions in air. The influence of various scratch parameters, such as the applied force, scan velocity and circle times, on the lithography patterns was investigated. The Pt-Cu-CuxO-Cu-Pt nanostructure was constructed by choosing suitable scratch parameters and oxidation at room temperature. The properties of the scratched regions were also investigated by friction force microscopy and conductive AFM (C-AFM). The I-V curves show symmetric and linear properties, and Ohmic contacts were formed. These results indicate that AFM mechanical lithography is a powerful tool for fabricating novel metal-semiconductor nanoelectronic devices.展开更多
Sodium titanate nanotubes have been prepared and modified chemically with CdSe quantum dots (QDs) using bifunctional modifiers (HS-COOH). Their photovoltaic characteristics have also been studied. The results indicate...Sodium titanate nanotubes have been prepared and modified chemically with CdSe quantum dots (QDs) using bifunctional modifiers (HS-COOH). Their photovoltaic characteristics have also been studied. The results indicate that the surface photovoltage response of nanotubes extends to the visible light region, and the intensity of surface photovoltage is enhanced after modification with CdSe QDs. The field-induced surface photovoltage spectroscopy (FISPS) shows that sodium titanate nanotubes have different photovoltaic response before and after modification. That is, the surface photovoltaic re-sponse of pure sodium titanate nanotubes increases with the enhancement of positive applied bias and decreases with the enhancement of negative applied bias. Meanwhile, the surface photovoltaic re-sponse of CdSe modified sodium titanate nanotubes is different from that of the pure sodium titanate nanotubes. The whole spectrum increases with the enhancement of applied bias at the first stage. However, when the applied bias reaches a certain value, the surface photovoltage response keeps in-creasing in some spectrum regions, while decreasing in other spectrum regions. This novel phe-nomenon is explained by using an electric field induced dipole model.展开更多
The ionic liquids containing Cd and Zn,which served as the metal-chalcogenides precursors,were synthesized and reacted with Na2S to synthesize the ionic-liquid-capped semiconductors. The products were detected by XRD ...The ionic liquids containing Cd and Zn,which served as the metal-chalcogenides precursors,were synthesized and reacted with Na2S to synthesize the ionic-liquid-capped semiconductors. The products were detected by XRD and TEM. The results demonstrated that the CdS was composed of 5―6 nm monodispersed nanocrystals. At the same time,the ZnO composed of 1 μm hexagonal-disk nanostructure was prepared under the same experimental condition. The difference of the morphology and structures between Zn and Cd systems was discussed by thermodynamics and crystallography. The fluorescence of as-prepared ZnO and CdS showed the excellent photoluminescence.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.90306010 and 20371015)State Key Basic Research'973'Plan of China(Grant No.2002CCC02700).
文摘Titanic acid nanotubes(H_(2)Ti_(2)O_(4)(OH)_(2))were surface-modified with cetyl alcohol through dehydration reaction because of existence of Ti–OH.The modified nanotubes were characterized by transmission electron microscopy(TEM),Fourier Transform Infrared(FT-IR)spectrometry and pho-toluminescence(PL)spectra.The results indicate that the modified nanotubes can be easily dis-persed into organic solvent such as chloroform and toluene in contrast with the unmodified nanotubes,which makes it easier to be assembled by LB technique.Moreover,the Ti-O-CH_(2)(CH_(2))_(14)CH_(3) on the surface of the nanotubes can hinder the adsorption of water and consequently the photoluminescence property of the nanotubes can be stabilized.Even though kept in humid condition or in air for a long time,the modified nanotubes also maintain the special photoluminescence property in the visible region.
基金Supported by the National Natural Science Foundation of China (Grant No. 90306010)the Program for New Century Excellent Talents in Uni-versity of China (Grant No. NCET-04-0653)+1 种基金the National Basic Research Program of China (Grant No. 2007CB616911)the Science and Technology Department of Henan Province (Grant No. 072300420100)
文摘Atomic Force Microscopy (AFM) mechanical lithography is a simple but significant method for nanofabrication. In this work, we used this method to construct nanos- tructures on Pt/Cu bilayer metal electrodes under ambient conditions in air. The influence of various scratch parameters, such as the applied force, scan velocity and circle times, on the lithography patterns was investigated. The Pt-Cu-CuxO-Cu-Pt nanostructure was constructed by choosing suitable scratch parameters and oxidation at room temperature. The properties of the scratched regions were also investigated by friction force microscopy and conductive AFM (C-AFM). The I-V curves show symmetric and linear properties, and Ohmic contacts were formed. These results indicate that AFM mechanical lithography is a powerful tool for fabricating novel metal-semiconductor nanoelectronic devices.
基金the Program for New Century Excellent Talents in University (Grant No. NCET-04-0653)973 Plan (Grant No. 2007CB616911)the National Natural Science Foundation of China (Grant Nos. 20371015 and 90306010)
文摘Sodium titanate nanotubes have been prepared and modified chemically with CdSe quantum dots (QDs) using bifunctional modifiers (HS-COOH). Their photovoltaic characteristics have also been studied. The results indicate that the surface photovoltage response of nanotubes extends to the visible light region, and the intensity of surface photovoltage is enhanced after modification with CdSe QDs. The field-induced surface photovoltage spectroscopy (FISPS) shows that sodium titanate nanotubes have different photovoltaic response before and after modification. That is, the surface photovoltaic re-sponse of pure sodium titanate nanotubes increases with the enhancement of positive applied bias and decreases with the enhancement of negative applied bias. Meanwhile, the surface photovoltaic re-sponse of CdSe modified sodium titanate nanotubes is different from that of the pure sodium titanate nanotubes. The whole spectrum increases with the enhancement of applied bias at the first stage. However, when the applied bias reaches a certain value, the surface photovoltage response keeps in-creasing in some spectrum regions, while decreasing in other spectrum regions. This novel phe-nomenon is explained by using an electric field induced dipole model.
基金Supported by the National Natural Science Foundation of China (Grant No. 20871041)the Key Project of Ministry of Education (Grant No. 208086)
文摘The ionic liquids containing Cd and Zn,which served as the metal-chalcogenides precursors,were synthesized and reacted with Na2S to synthesize the ionic-liquid-capped semiconductors. The products were detected by XRD and TEM. The results demonstrated that the CdS was composed of 5―6 nm monodispersed nanocrystals. At the same time,the ZnO composed of 1 μm hexagonal-disk nanostructure was prepared under the same experimental condition. The difference of the morphology and structures between Zn and Cd systems was discussed by thermodynamics and crystallography. The fluorescence of as-prepared ZnO and CdS showed the excellent photoluminescence.
