Intraband Relaxation Dynamics of Charge Carriers within CdTe Quantum Wires
Intraband Relaxation Dynamics of Charge Carriers within CdTe Quantum Wires
复制标题
CdTe 量子线内电荷载流子的带内弛豫动力学
DOI：
10.1021/acs.jpclett.0c01326
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Loomis, Richard A.
中科院分区：
文献类型：
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作者：
Sanderson, William M.;Wang, Fudong;Schrier, Joshua;Buhro, William E.;Loomis, Richard A.
利用瞬态吸收光谱研究了CdTe量子线中光生载流子的态-态带内弛豫动力学。使用量子态重整化模型分离来自量子限制特征的能量移位和与这些特征相关联的状态中的载流子的占用的重叠信号。用2.75 eV的激发能量产生的空穴到达测量的仪器响应内的带边缘，Δ 200 fs。这种极短的弛豫时间与量子阱的低光致发光量子产率（约0.2%）以及空穴的替代弛豫路径的存在是一致的。电子通过不同的能量可用的量子限制状态，可能是通过声子耦合，与一个总的速率为10.6 eV ps-1的放松。
The state-to-state intraband relaxation dynamics of charge carriers photogenerated within CdTe quantum wires (QWs) are characterized via transient absorption spectroscopy. Overlapping signals from the energetic-shifting of the quantum-confinement features and the occupancy of carriers in the states associated with these features are separated using the quantum-state renormalization model. Holes generated with an excitation energy of 2.75 eV reach the band edge within the instrument response of the measurement, ∼200 fs. This extremely short relaxation time is consistent with the low photoluminescence quantum yield of the QWs, ∼0.2%, and the presence of alternative relaxation pathways for the holes. The electrons relax through the different energetically available quantum-confinement states, likely via phonon coupling, with an overall rate of ∼0.6 eV ps–1.