Berciaud Stéphane, Cognet Laurent, Lounis Brahim
Centre de Physique Moléculaire Optique et Hertzienne, Université de Bordeaux and CNRS, 351 cours de la Libération, Talence, F-33405, France.
Phys Rev Lett. 2008 Aug 15;101(7):077402. doi: 10.1103/PhysRevLett.101.077402. Epub 2008 Aug 14.
The absorption cross section of highly luminescent individual single-walled carbon nanotubes is determined using time-resolved and cw luminescence spectroscopy. A mean value of approximately 1 x 10(-17) cm2 per carbon atom is obtained for (6,5) tubes excited at their second optical transition, and corroborated by single tube photothermal absorption measurements. Biexponential luminescence decays are systematically observed, with short and long lifetimes around 45 and 250 ps. This behavior is attributed to the band edge exciton fine structure with a dark level lying a few meV below a bright one.
使用时间分辨和连续波发光光谱法测定了高发光性的单个单壁碳纳米管的吸收截面。对于在其第二个光学跃迁处激发的(6,5)管，获得了每个碳原子约1×10(-17)平方厘米的平均值，并通过单管光热吸收测量得到了证实。系统地观察到双指数发光衰减，短寿命和长寿命分别约为45皮秒和250皮秒。这种行为归因于带边激子精细结构，其中暗能级比亮能级低几个毫电子伏特。
