Georgi Carsten, Hartmann Nicolai, Gokus Tobias, Green Alexander A, Hersam Mark C, Hartschuh Achim
Department Chemie und Biochemie and CeNS, Ludwig-Maximilians-Universität, 81377 München, Germany.
Chemphyschem. 2008 Jul 14;9(10):1460-4. doi: 10.1002/cphc.200800179.
The temporal evolution of photoluminescence in individual single-walled carbon nanotubes (SWNT) under strong laser irradiation is studied and pronounced blinking and bleaching is observed, caused by photoinduced oxidation that subsequently quenches mobile excitons. The nanotubes are isolated with sodium cholate and spun onto either a glass or mica surface. Their bleaching behavior is investigated for variable laser intensities in air and argon atmosphere. The decay rate for luminescence bleaching generally increases with higher laser intensity, however saturating on mica substrates, which is attributed to limited availability of oxygen in the vicinity of the nanotubes. Step-like events in the luminescence time traces corresponding to single oxidation events are analyzed regarding relative step height and suggest an exciton diffusion range of about 105 nm.
研究了单个单壁碳纳米管（SWNT）在强激光照射下光致发光的时间演化，观察到明显的闪烁和漂白现象，这是由光致氧化引起的，随后光致氧化淬灭了移动激子。纳米管用胆酸钠分离并旋涂到玻璃或云母表面上。研究了它们在空气和氩气气氛中不同激光强度下的漂白行为。发光漂白的衰减率通常随着激光强度的增加而增加，但在云母衬底上达到饱和，这归因于纳米管附近氧气的可用性有限。分析了与单个氧化事件相对应的发光时间轨迹中的阶梯状事件的相对阶梯高度，结果表明激子扩散范围约为105 nm。
