Origin of low-energy photoluminescence peaks in single carbon nanotubes: K-momentum dark excitons and triplet dark excitons
Origin of low-energy photoluminescence peaks in single carbon nanotubes: K-momentum dark excitons and triplet dark excitons
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DOI：
10.1103/physrevb.81.033401
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发表时间：
2010-01-01
影响因子：
3.7
通讯作者：
Kanemitsu, Yoshihiko
中科院分区：
文献类型：
--
作者：
Matsunaga, Ryusuke;Matsuda, Kazunari;Kanemitsu, Yoshihiko
我们对单根碳纳米管进行了光致发光（PL）光谱研究，以研究卫星PL峰，其能量远低于最低（E-11）亮激子峰。从PL谱的温度和管径依赖性，我们澄清了两个起源的低能PL峰。弱峰位于E-11亮激子态下方约130 meV处，可以用最低亮激子态上方K动量暗激子态的声子边带很好地解释。此外，脉冲激光辐照后，出现了一个强的PL峰，其峰值能量强烈依赖于管的直径。该PL峰来自三重态暗激子态。
We performed photoluminescence (PL) spectroscopy on single carbon nanotubes to investigate the satellite PL peaks, which are much lower in energy than the lowest (E-11) bright exciton peak. From the temperature and tube-diameter dependences of the PL spectra, we clarified two origins of the low-energy PL peaks. The weak peak, lying about 130 meV below the E-11 bright exciton state, is well explained by the phonon sideband of the K-momentum dark exciton states above the lowest-bright exciton state. In addition, a strong PL peak appears after pulsed-laser irradiation, and its peak energy depends strongly on the tube diameter. This PL peak comes from the triplet dark exciton states.