Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215, USA.
ACS Nano. 2011 Jan 25;5(1):647-55. doi: 10.1021/nn1031214. Epub 2010 Dec 17.
We perform Monte Carlo simulations of the time-resolved, spatially resolved, and integrated photoluminescence from a nanotube to investigate the role of the nanotube length L and defects using an exciton random-walk and defect-induced quenching model. When nonradiative decay is due solely to diffusion quenching, the quantum efficiency is approximately proportional to L2 at low quantum efficiency. With defects present, the quantum efficiency depends only weakly on the number defects but is instead tied to Leff2 where Leff is the root-mean-square separation between defects. The time-resolved photoluminescence decay of nanotubes is multiexponential for both pristine nanotubes and nanotubes with defects. The dominant time scale for a pristine nanotube is proportional to L2/D, where D is the diffusion constant. The presence of defects on the nanotube introduces additional time scales.
我们进行了时间分辨、空间分辨和积分光致发光的蒙特卡罗模拟，以研究使用激子随机行走和缺陷诱导猝灭模型的纳米管长度 L 和缺陷的作用。当非辐射衰减仅由于扩散猝灭时，量子效率在低量子效率下大约与 L2 成正比。存在缺陷时，量子效率仅与缺陷的数量弱相关，但与 Leff2 相关，其中 Leff 是缺陷之间均方根分离的平方根。对于原始纳米管和具有缺陷的纳米管，纳米管的时间分辨光致发光衰减都是多指数的。原始纳米管的主要时间尺度与 L2/D 成正比，其中 D 是扩散常数。纳米管上存在缺陷会引入额外的时间尺度。
