Self-Trapping of Charge Carriers in Semiconducting Carbon Nanotubes: Structural Analysis

详细信息    查看全文

• 作者：Lyudmyla Adamska ; George V. Nazin ; Stephen K. Doorn ; Sergei Tretiak
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2015
• 出版时间：October 1, 2015
• 年：2015
• 卷：6
• 期：19
• 页码：3873-3879
• 全文大小：530K
• ISSN：1948-7185

文摘

The spatial extent of charged electronic states in semiconducting carbon nanotubes with indices (6,5) and (7,6) was evaluated using density functional theory. It was observed that electrons and holes self-trap along the nanotube axis on length scales of about 4 and 8 nm, respectively, which localize cations and anions on comparable length scales. Self-trapping is accompanied by local structural distortions showing periodic bond-length alternation. The average lengthening (shortening) of the bonds for anions (cations) is expected to shift the G-mode frequency to lower (higher) values. The smaller-diameter nanotube has reduced structural relaxation due to higher carbon鈥揷arbon bond strain. The reorganization energy due to charge-induced deformations in both nanotubes is found to be in the 30鈥?0 meV range. Our results represent the first theoretical simulation of self-trapping of charge carriers in semiconducting nanotubes, and agree with available experimental data.