Nonradiative quenching of fluorescence in a semiconducting carbon nanotube:: A time-domain ab initio study
Nonradiative quenching of fluorescence in a semiconducting carbon nanotube:: A time-domain ab initio study
复制标题
DOI：
10.1103/physrevlett.100.197402
复制
发表时间：
2008-05-16
影响因子：
8.6
通讯作者：
Prezhdo, Oleg V.
中科院分区：
文献类型：
--
作者：
Habenicht, Bradley F.;Prezhdo, Oleg V.
如实验所示，强非辐射衰减通道存在于碳纳米管（CNT）和负责低荧光产率。在Kohn-Sham表示中，在具有表面跳跃的（6，4）半导体CNT中模拟了电子激发到其基态的衰减，提供了荧光猝灭的独特时域原子描述。理想碳纳米管的衰变估计发生在150 ps的时间尺度上，并且仅弱依赖于温度。振动诱导退相干强烈影响电子弛豫。缺陷使激发态寿命减少到几十皮秒，从而使实验中看到的多个衰变时间尺度合理化。
As shown experimentally, strong nonradiative decay channels exist in carbon nanotubes (CNT) and are responsible for low fluorescence yields. The decay of the electronic excitation to its ground state is simulated in the (6,4) semiconducting CNT with surface hopping in the Kohn-Sham representation, providing a unique time-domain atomistic description of fluorescence quenching. The decay in the ideal CNT is estimated to occur on a 150 ps time scale and is only weakly dependent on temperature. Vibrationally induced decoherence strongly influences the electronic relaxation. Defects decrease the excited state lifetime to tens of picoseconds, rationalizing the multiple decay time scales seen in experiments.