TY - JOUR
T1 - Long-Lived 1D Excitons in Bright CdTe Quantum Wires
AU - Sanderson, William M.
AU - Wang, Fudong
AU - Buhro, William E.
AU - Loomis, Richard A.
N1 - Publisher Copyright:
Copyright © 2019 American Chemical Society.
PY - 2019/2/7
Y1 - 2019/2/7
N2 - Time-resolved photoluminescence (PL) intensity decay profiles were recorded for room-temperature ensemble samples of CdTe quantum wires (QWs) with varying PL quantum yields (? PL ). The PL lifetimes for samples with ? PL > 4% are nearly an order of magnitude greater than the radiative lifetime of CdTe QDs, ≥200 versus ?25 ns. The photogenerated electron-hole pairs relax to the lowest exciton state, correlating with the 1? e and 1? 3/2h quantum-confinement states, and are bound together as one-dimensional (1D) excitons. These 1D excitons have a thermal distribution of translational kinetic energy along the long, unconfined dimension of the QWs. The extended lifetimes are justified via the constraints imposed by the conservation of wave vector (or momentum) and the large mismatch between the wave vector of the moving 1D excitons and of the photons emitted during radiative relaxation. The long charge-carrier lifetimes and the dimensionality of these high-quality semiconductor QWs offer distinct advantages for use in photovoltaics.
AB - Time-resolved photoluminescence (PL) intensity decay profiles were recorded for room-temperature ensemble samples of CdTe quantum wires (QWs) with varying PL quantum yields (? PL ). The PL lifetimes for samples with ? PL > 4% are nearly an order of magnitude greater than the radiative lifetime of CdTe QDs, ≥200 versus ?25 ns. The photogenerated electron-hole pairs relax to the lowest exciton state, correlating with the 1? e and 1? 3/2h quantum-confinement states, and are bound together as one-dimensional (1D) excitons. These 1D excitons have a thermal distribution of translational kinetic energy along the long, unconfined dimension of the QWs. The extended lifetimes are justified via the constraints imposed by the conservation of wave vector (or momentum) and the large mismatch between the wave vector of the moving 1D excitons and of the photons emitted during radiative relaxation. The long charge-carrier lifetimes and the dimensionality of these high-quality semiconductor QWs offer distinct advantages for use in photovoltaics.
UR - https://www.scopus.com/pages/publications/85060831395
U2 - 10.1021/acs.jpcc.8b09588
DO - 10.1021/acs.jpcc.8b09588
M3 - Article
AN - SCOPUS:85060831395
SN - 1932-7447
VL - 123
SP - 3144
EP - 3151
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 5
ER -