Field-effect transistors （FETs） have been fabricated using as-grown single-walled carbon nanotubes （SWNTs） for the channel as well as both source and drain electrodes. The underlying Si substrate was employed as t...Field-effect transistors （FETs） have been fabricated using as-grown single-walled carbon nanotubes （SWNTs） for the channel as well as both source and drain electrodes. The underlying Si substrate was employed as the back-gate electrode. Fabrication consisted of patterned catalyst deposition by surface modification followed by dip-coating and synthesis of SWNTs by alcohol chemical vapor deposition （CVD）. The electrodes and channel were grown simultaneously in one CVD process. The resulting FETs exhibited excellent performance, with an I ON/I OFF ratio of 10^6 and a maximum ON-state current （/ON） exceeding 13 uA. The large I ON is attributed to SWNT bundles connecting the SWNT channel with the SWNT electrodes. Bundling creates a large contact area, which results in a small contact resistance despite the presence of Schottky barriers at metallic-semiconducting interfaces. The approach described here demonstrates a significant step toward the realization of metal-free electronics.展开更多
In nature,many living organisms exhibit low-angle-dependent or even angle-independent structural colors for wide viewing angle,such as the blue skin of mandrill,feather of blue bird and shell of longhorn beetle,etc.To...In nature,many living organisms exhibit low-angle-dependent or even angle-independent structural colors for wide viewing angle,such as the blue skin of mandrill,feather of blue bird and shell of longhorn beetle,etc.To mimic these structural colors,based on periodic semicircular micro-grooved(PSMG) substrate,silica colloidal photonic crystals provide anisotropic angle-independent structural colors.The PSMG photonic crystals were fabricated by self-assembling monodispersed silica nanoparticles on a micro-grooved template,which can be easily prepared in large scale by a hot embossing method,and no additional materials are needed in the whole preparation process.The PSMG photonic crystals exhibit identical structural colors around the groove axis,whereas it is angle-dependent along the groove axis.In addition,this PSMG surface of photonic crystal also leads to color separation effect and monocolor polarization conversion.This system provides a facile and scalable means to prepare anisotropically angleindependent colloidal photonic crystal,which is considered important in applications in the field of anti-counterfeiting or the manufacture of monochromatic light reflector with wide viewing angles and other novel optical devices.展开更多
文摘Field-effect transistors （FETs） have been fabricated using as-grown single-walled carbon nanotubes （SWNTs） for the channel as well as both source and drain electrodes. The underlying Si substrate was employed as the back-gate electrode. Fabrication consisted of patterned catalyst deposition by surface modification followed by dip-coating and synthesis of SWNTs by alcohol chemical vapor deposition （CVD）. The electrodes and channel were grown simultaneously in one CVD process. The resulting FETs exhibited excellent performance, with an I ON/I OFF ratio of 10^6 and a maximum ON-state current （/ON） exceeding 13 uA. The large I ON is attributed to SWNT bundles connecting the SWNT channel with the SWNT electrodes. Bundling creates a large contact area, which results in a small contact resistance despite the presence of Schottky barriers at metallic-semiconducting interfaces. The approach described here demonstrates a significant step toward the realization of metal-free electronics.
基金supported by the National Key Research and Development Program of China(2016YFA0200800, 2013CB834505)he National Natural Science Foundation of China(U1430128,21503244)
文摘In nature,many living organisms exhibit low-angle-dependent or even angle-independent structural colors for wide viewing angle,such as the blue skin of mandrill,feather of blue bird and shell of longhorn beetle,etc.To mimic these structural colors,based on periodic semicircular micro-grooved(PSMG) substrate,silica colloidal photonic crystals provide anisotropic angle-independent structural colors.The PSMG photonic crystals were fabricated by self-assembling monodispersed silica nanoparticles on a micro-grooved template,which can be easily prepared in large scale by a hot embossing method,and no additional materials are needed in the whole preparation process.The PSMG photonic crystals exhibit identical structural colors around the groove axis,whereas it is angle-dependent along the groove axis.In addition,this PSMG surface of photonic crystal also leads to color separation effect and monocolor polarization conversion.This system provides a facile and scalable means to prepare anisotropically angleindependent colloidal photonic crystal,which is considered important in applications in the field of anti-counterfeiting or the manufacture of monochromatic light reflector with wide viewing angles and other novel optical devices.
