For nanotube-based electronics to become a viable alternative to silicon technology,high-density aligned carbon nanotubes are essential.In this paper,we report the combined use of low-pressure chemical vapor depositio...For nanotube-based electronics to become a viable alternative to silicon technology,high-density aligned carbon nanotubes are essential.In this paper,we report the combined use of low-pressure chemical vapor deposition and stacked multiple transfer to achieve high-density aligned nanotubes.By using an optimized nanotube synthesis recipe,we have achieved high-density aligned carbon nanotubes with density as high as 30 tubes/μm.In addition,a facile stacked multiple transfer technique has been developed to further increase the nanotube density to 55 tubes/μm.Furthermore,high-performance submicron carbon nanotube field-effect transistors have been fabricated on the high-density aligned nanotubes.Before removing the metallic nanotubes by electrical breakdown,the devices exhibit on-current density of 92.4μA/μm and normalized transconductance of 13.3μS/μm.Moreover,benchmarking with the aligned carbon nanotube transistors in the literature indicates that our devices exhibit the best performance so far,which is attributed to both the increased nanotube density and scaling down of channel length.This study shows the great potential of using such high-density aligned nanotubes for high performance nanoelectronics and analog/RF applications.展开更多
In this paper, we report polyfluorene-separated ultra-high purity semiconducting carbon nanotube radio frequency transistors with a self-aligned T-shape gate structure. Because of the ultra-high semiconducting tube pu...In this paper, we report polyfluorene-separated ultra-high purity semiconducting carbon nanotube radio frequency transistors with a self-aligned T-shape gate structure. Because of the ultra-high semiconducting tube purity and self-aligned T-shape gate structure, these transistors showed an excellent direct current and radio frequency performance. In regard to the direct current characteristics, these transistors showed a transconductance up to 40μS/μm and an excellent current saturation behavior with an output resistance greater than 200 kΩ·μm. In terms of the radio frequency characteristics, an extrinsic maximum oscillation frequency （fmax） of 19 GHz was achieved, which is a record among all kinds of carbon nanotube transistors, and an extrinsic current gain cut-off frequency （fT） of 22 GHz was achieved, which is the highest among transistors based on carbon nanotube networks. Our results take the radio frequency performance of carbon nanotube transistors to a new level and can further accelerate the application of carbon nanotubes for future radio frequency electronics.展开更多
基金the Focus Center Research Program(FCRP)-Center on Func-tional Engineered Nano Architectonics(FENA)Joint King Abdulaziz City for Science and Technology(KACST)/California Center of Excellence on Nano Science and Engineering for Green and Clean Tech-nologiesthe National Science Foundation(Nos.CCF-0726815 and CCF-0702204).
文摘For nanotube-based electronics to become a viable alternative to silicon technology,high-density aligned carbon nanotubes are essential.In this paper,we report the combined use of low-pressure chemical vapor deposition and stacked multiple transfer to achieve high-density aligned nanotubes.By using an optimized nanotube synthesis recipe,we have achieved high-density aligned carbon nanotubes with density as high as 30 tubes/μm.In addition,a facile stacked multiple transfer technique has been developed to further increase the nanotube density to 55 tubes/μm.Furthermore,high-performance submicron carbon nanotube field-effect transistors have been fabricated on the high-density aligned nanotubes.Before removing the metallic nanotubes by electrical breakdown,the devices exhibit on-current density of 92.4μA/μm and normalized transconductance of 13.3μS/μm.Moreover,benchmarking with the aligned carbon nanotube transistors in the literature indicates that our devices exhibit the best performance so far,which is attributed to both the increased nanotube density and scaling down of channel length.This study shows the great potential of using such high-density aligned nanotubes for high performance nanoelectronics and analog/RF applications.
文摘In this paper, we report polyfluorene-separated ultra-high purity semiconducting carbon nanotube radio frequency transistors with a self-aligned T-shape gate structure. Because of the ultra-high semiconducting tube purity and self-aligned T-shape gate structure, these transistors showed an excellent direct current and radio frequency performance. In regard to the direct current characteristics, these transistors showed a transconductance up to 40μS/μm and an excellent current saturation behavior with an output resistance greater than 200 kΩ·μm. In terms of the radio frequency characteristics, an extrinsic maximum oscillation frequency （fmax） of 19 GHz was achieved, which is a record among all kinds of carbon nanotube transistors, and an extrinsic current gain cut-off frequency （fT） of 22 GHz was achieved, which is the highest among transistors based on carbon nanotube networks. Our results take the radio frequency performance of carbon nanotube transistors to a new level and can further accelerate the application of carbon nanotubes for future radio frequency electronics.
