Large quantities of gallium nitride(GaN) nanowires have been prepared via ammoniating the Ga2O3 films deposited on the oxidized aluminum layer at 950 ℃ in a quartz tube. The nanowires have been confirmed as crystalli...Large quantities of gallium nitride(GaN) nanowires have been prepared via ammoniating the Ga2O3 films deposited on the oxidized aluminum layer at 950 ℃ in a quartz tube. The nanowires have been confirmed as crystalline wurtzite GaN by X-ray diffraction, X-ray photoelectron spectrometry scanning electron microscope and selected-area electron diffraction. Transmission electron microscope(TEM) and scanning electron microscopy(SEM) reveal that the nanowires are amorphous and irregular, with diameters ranging from 30 nm to 80 nm and lengths up to tens of microns. Selected-area electron diffraction indicates that the nanowire with the hexagonal wurtzite structure is the single crystalline. The growth mechanism is discussed briefly.展开更多
Nanosize CdS semiconductor particles were synthesized using the solvothermal technique. The structure was characterized by means of XRD,TEM and ED techniques. PANI film was prepared by electro-chemistry method onto th...Nanosize CdS semiconductor particles were synthesized using the solvothermal technique. The structure was characterized by means of XRD,TEM and ED techniques. PANI film was prepared by electro-chemistry method onto the indium-tin oxide glass. The nanoparticles were doped on PANI film by the dipping process, and the self-assembled nanoparticles-PANI composite film was acquired. The photoelectric properties of the self-assembled film were studied by PL and Z-scan method.展开更多
Patterned porous silicon （PS） films were synthesised by using bydrogen ion implantation technique and typical electrochemical anodic etching method.The surface morphology and characteristics of the PS films were cha...Patterned porous silicon （PS） films were synthesised by using bydrogen ion implantation technique and typical electrochemical anodic etching method.The surface morphology and characteristics of the PS films were characterized by scanning electron microscopy （SEM）,X-ray diffraction（XRD）,and atomic force microscopy （AFM）.The efficient electron field emission with low turn-on field of about 3.5V/μm was obtained at current density of 0.1μA/cm^2.The electron field emission current density from the patterned PS films reached 1mA/cm^2 under and applied field of about 12.5V/μm.The experimental results show that the patterned PS films are of certain practical significance and are valuable for flat panel displays.展开更多
We have developed a process for chemical purification of carbon nanotubes for solution-processable thin-film transistors （TFTs） having high mobility. Films of the purified carbon nanotubes fabricated by simple drop ...We have developed a process for chemical purification of carbon nanotubes for solution-processable thin-film transistors （TFTs） having high mobility. Films of the purified carbon nanotubes fabricated by simple drop coating showed carrier mobilities as high as 164 cm2V-1s -1 normalized transconductances of 0.78 Sm-1 and on/off current ratios of 10^6. Such high performance requires the preparation of a suspension of micrometer-long and highly purified semiconducting single-walled carbon nanotubes （SWCNTs）. Our purification process includes length and electronic-type selective trapping of SWCNTs using recycling gel filtration with a mixture of surfactants. The results provide an important milestone toward printed high-speed and large-area electronics with roll-to-roll and ink-jet device fabrication.展开更多
Here we report a simple and scalable method to fabricate high performance thin-film field-effect transistors(FETs) with high yield based on chemically functionalized single-walled carbon nanotubes(SWNTs) by organic ra...Here we report a simple and scalable method to fabricate high performance thin-film field-effect transistors(FETs) with high yield based on chemically functionalized single-walled carbon nanotubes(SWNTs) by organic radical initiators.The UV-Vis-NIR spectra,Raman spectra and electrical characterization demonstrated that metallic species in CoMoCat 65 and HiPco SWNTs could be effectively eliminated after reaction with some organic radical initiators.The effects of the substrate properties on the electrical properties of FET devices were investigated,and the results showed that the electrical properties of FET devices fabricated on high hydrophobic substrates were better than those on low hydrophobic substrates.Furthermore,it was found that FET devices based on 1,1'-azobis(cyanocyclohexane)(ACN)-modified CoMoCat 65 SWNTs exhibited more excellent electrical performance with effective mobility of ～11.8 cm2/Vs and on/off ratio of ～2×105 as compared with benzoyl peroxide(BPO)-modified CoMoCat 65 SWNTs and lauoryl peroxideand(LPO)-modified HiPco SWNTs,likely due to the introduction of the electron-withdrawing groups(CN group) on the SWNT surface.This method does not require nontrivial reaction conditions or complicated purification after reaction,therefore promising low-cost production of high-performance devices for macroelectronics.展开更多
基金National Natural Science Foundation of China(90301002and90201025)
文摘Large quantities of gallium nitride(GaN) nanowires have been prepared via ammoniating the Ga2O3 films deposited on the oxidized aluminum layer at 950 ℃ in a quartz tube. The nanowires have been confirmed as crystalline wurtzite GaN by X-ray diffraction, X-ray photoelectron spectrometry scanning electron microscope and selected-area electron diffraction. Transmission electron microscope(TEM) and scanning electron microscopy(SEM) reveal that the nanowires are amorphous and irregular, with diameters ranging from 30 nm to 80 nm and lengths up to tens of microns. Selected-area electron diffraction indicates that the nanowire with the hexagonal wurtzite structure is the single crystalline. The growth mechanism is discussed briefly.
文摘Nanosize CdS semiconductor particles were synthesized using the solvothermal technique. The structure was characterized by means of XRD,TEM and ED techniques. PANI film was prepared by electro-chemistry method onto the indium-tin oxide glass. The nanoparticles were doped on PANI film by the dipping process, and the self-assembled nanoparticles-PANI composite film was acquired. The photoelectric properties of the self-assembled film were studied by PL and Z-scan method.
基金National Natural Science Foundation of China (60476004) Foundation of Graduate Students of East ChinaNormal University(ECNU2005) Foundation of State Key Laboratory of Advanced Technology for MaterialsSynthesis and Processing( Wuhan University of Tech
文摘Patterned porous silicon （PS） films were synthesised by using bydrogen ion implantation technique and typical electrochemical anodic etching method.The surface morphology and characteristics of the PS films were characterized by scanning electron microscopy （SEM）,X-ray diffraction（XRD）,and atomic force microscopy （AFM）.The efficient electron field emission with low turn-on field of about 3.5V/μm was obtained at current density of 0.1μA/cm^2.The electron field emission current density from the patterned PS films reached 1mA/cm^2 under and applied field of about 12.5V/μm.The experimental results show that the patterned PS films are of certain practical significance and are valuable for flat panel displays.
文摘We have developed a process for chemical purification of carbon nanotubes for solution-processable thin-film transistors （TFTs） having high mobility. Films of the purified carbon nanotubes fabricated by simple drop coating showed carrier mobilities as high as 164 cm2V-1s -1 normalized transconductances of 0.78 Sm-1 and on/off current ratios of 10^6. Such high performance requires the preparation of a suspension of micrometer-long and highly purified semiconducting single-walled carbon nanotubes （SWCNTs）. Our purification process includes length and electronic-type selective trapping of SWCNTs using recycling gel filtration with a mixture of surfactants. The results provide an important milestone toward printed high-speed and large-area electronics with roll-to-roll and ink-jet device fabrication.
基金supported by the Scientific Research Fund of Hunan Provincial Education Department(09B084)the Opening Project of Key Laboratory of Photochemical Conversion and Optoelectronic Materials,TIPC, Chinese Academy of Sciences(PCOM201114)
文摘Here we report a simple and scalable method to fabricate high performance thin-film field-effect transistors(FETs) with high yield based on chemically functionalized single-walled carbon nanotubes(SWNTs) by organic radical initiators.The UV-Vis-NIR spectra,Raman spectra and electrical characterization demonstrated that metallic species in CoMoCat 65 and HiPco SWNTs could be effectively eliminated after reaction with some organic radical initiators.The effects of the substrate properties on the electrical properties of FET devices were investigated,and the results showed that the electrical properties of FET devices fabricated on high hydrophobic substrates were better than those on low hydrophobic substrates.Furthermore,it was found that FET devices based on 1,1'-azobis(cyanocyclohexane)(ACN)-modified CoMoCat 65 SWNTs exhibited more excellent electrical performance with effective mobility of ～11.8 cm2/Vs and on/off ratio of ～2×105 as compared with benzoyl peroxide(BPO)-modified CoMoCat 65 SWNTs and lauoryl peroxideand(LPO)-modified HiPco SWNTs,likely due to the introduction of the electron-withdrawing groups(CN group) on the SWNT surface.This method does not require nontrivial reaction conditions or complicated purification after reaction,therefore promising low-cost production of high-performance devices for macroelectronics.
