Sanderson WM, Wang F, Schrier J, Buhro WE, Loomis RA. Intraband Relaxation Dynamics of Charge Carriers within CdTe Quantum Wires.
J Phys Chem Lett 2020;
11:4901-4910. [PMID:
32491860 DOI:
10.1021/acs.jpclett.0c01326]
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Abstract
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.
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