利用高分辨率近场显微镜研究单壁碳纳米管中的激子局域化。

Probing exciton localization in single-walled carbon nanotubes using high-resolution near-field microscopy.

机构信息

Department Chemie and CeNS, Ludwig-Maximilians-Universität München, 81377 München, Germany.

出版信息

ACS Nano. 2010 Oct 26;4(10):5914-20. doi: 10.1021/nn101443d.

PMID:20857945

Abstract

We observe localization of excitons in semiconducting single-walled carbon nanotubes at room temperature using high-resolution near-field photoluminescence (PL) microscopy. Localization is the result of spatially confined exciton energy minima with depths of more than 15 meV connected to lateral energy gradients exceeding 2 meV/nm as evidenced by energy-resolved PL imaging. Simulations of exciton diffusion in the presence of energy variations support this interpretation predicting strongly enhanced PL at local energy minima.

摘要

我们使用高分辨率近场光致发光（PL）显微镜观察到半导体单壁碳纳米管中激子在室温下的局域化。局域化是由于空间限制的激子能谷深度超过 15 毫电子伏特（meV），与侧向能量梯度超过 2 毫电子伏特每纳米（meV/nm）有关，这一点可以通过能量分辨 PL 成像得到证明。在存在能量变化的情况下，激子扩散的模拟支持这种解释，预测在局部能量最小值处会产生强烈增强的 PL。