Optical Spectroscopy of Doped Carbon Nanotubes
Optical Spectroscopy of Doped Carbon Nanotubes
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掺杂碳纳米管的光谱分析
DOI：
10.1142/9789813235465_0013
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Tobias Hertel
中科院分区：
文献类型：
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作者：
Tobias Hertel
对于使现代信息和通信时代成为可能的许多设备技术来说，控制半导体中的电荷是关键。通过化学或物理方法掺杂的目的是提供移动载流子，从而促进关键的半导体器件功能。本章讨论了用于掺杂的还原或氧化半导体单壁碳纳米管(S-SWCNTs)的制备和光学表征的一些方面。我们将重点放在氧化还原和电化学修饰上，以说明我们目前的理解在多大程度上不仅允许对杂质浓度进行定性评估，还允许对杂质浓度进行定量光谱评估。有些令人惊讶的是，我们发现常用的n-orp掺杂方案似乎导致了不均匀的载流子分布，一些多余的电子或空穴被深的库仑陷阱固定。这种载体的局部化被认为是低维材料如单壁碳纳米管屏蔽能力较弱以及对环境扰动的明显敏感性的症状。这些发现也可能对用纳米材料制造功能半导体器件有更广泛的影响。
Controlling charges in semiconductors is key for many of the device technologies that enable the modern information and communication age. Doping by chemical or physical means is intended to provide mobile charge carriers which facilitate crucial semiconductor device functionality. This chapter discusses some of the aspects related to the fabrication and optical characterization of reduced or oxidized semiconducting single-wall carbon nanotubes (s-SWCNTs) for the purpose of doping. We focus on redox- and electro-chemical modification to illustrate how far our current understanding allows not only a qualitative but also a quantitative spectroscopic assessment of impurity concentrations. Somewhat surprisingly, we find that commonly usedn- orp-doping schemes appear to lead to inhomogeneous carrier distributions with some excess electrons or holes immobilized by deep Coulomb traps. Such carrier localization is believed to be symptomatic of the weak screening and pronounced susceptibility to environmental perturbations of low-dimensional materials such as SWCNTs. These findings may also have broader implications for the fabrication of functional semiconductor devices from nanoscale materials.