Laser-induced nanoscale thermocapillary flow for purification of aligned arrays of single-walled carbon nanotubes.
Laser-induced nanoscale thermocapillary flow for purification of aligned arrays of single-walled carbon nanotubes.
复制标题
DOI：
10.1021/nn505566r
复制
发表时间：
2014-12
期刊：
影响因子：
17.1
通讯作者：
Frank Du;J. Felts;Xu Xie;Jizhou Song;Yuhang Li;M. Rosenberger;A. Islam;S. Jin;S. Dunham
中科院分区：
文献类型：
--
作者：
Frank Du;J. Felts;Xu Xie;Jizhou Song;Yuhang Li;M. Rosenberger;A. Islam;S. Jin;S. Dunham
尽管单壁碳纳米管 (SWNT) 排列阵列在广泛的先进半导体器件中具有巨大的应用潜力，但传统生长技术产生的金属性 SWNT (m-SWNT) 数量相对较多，导致性能显着下降。最近报道的基于热毛细管效应的方法能够从此类阵列中去除 m-SWNT，提供了卓越的效率水平，但程序很麻烦并且需要多个处理步骤。在这里，我们提出了一种简单、稳健的替代方案，通过红外激光照射产生原始的纯半导体单壁碳纳米管 (s-SWNT) 阵列。涂有有机薄膜的 m-SWNT 的选择性吸收引发纳米级热毛细管流动，导致仅 m-SWNT 暴露。反应离子蚀刻消除了 m-SWNT，而不损坏 s-SWNT；除去薄膜完成纯化。热物理的系统实验研究和计算模型阐明了这一过程的基本方面。演示包括使用以这种方式形成的 s-SWNT 阵列作为统计相关数量的晶体管中的半导体沟道材料，以实现高迁移率 (>900 cm2 V(-1) s(-1)) 和开关比 (>10(4))。统计分析表明，阵列包含至少 99.8% 的 s-SWNT，并且可能更高。
Although aligned arrays of single-walled carbon nanotubes (SWNTs) have outstanding potential for use in broad classes of advanced semiconductor devices, the relatively large population of metallic SWNTs (m-SWNTs) that results from conventional growth techniques leads to significantly degraded performance. Recently reported methods based on thermocapillary effects that enable removal of m-SWNTs from such arrays offer exceptional levels of efficiency, but the procedures are cumbersome and require multiple processing steps. Here we present a simple, robust alternative that yields pristine arrays of purely semiconducting SWNTs (s-SWNTs) by use of irradiation with an infrared laser. Selective absorption by m-SWNTs coated with a thin organic film initiates nanoscale thermocapillary flows that lead to exposure only of the m-SWNTs. Reactive ion etching eliminates the m-SWNTs without damaging the s-SWNTs; removal of the film completes the purification. Systematic experimental studies and computational modeling of the thermal physics illuminates the essential aspects of this process. Demonstrations include use of arrays of s-SWNTs formed in this manner as semiconducting channel materials in statistically relevant numbers of transistors to achieve both high mobilities (>900 cm2 V(-1) s(-1)) and switching ratios (>10(4)). Statistical analysis indicates that the arrays contain at least 99.8% s-SWNTs and likely significantly higher.