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Title: Photoexcited Electron Lifetimes Influenced by Momentum Dispersion in Silicon Nanowires

Abstract

Silicon nanowires (SiNWs) exhibit unique optoelectronic properties originating from one-dimensional confinement effect. Technologically relevant properties—including band gap, radiative and nonradiative transitions, and charge carrier relaxation rates—are influenced by sampling of momentum along the growth direction. In this work, we quantify the influence of momentum dispersion on hot-electron relaxation rates and nonradiative lifetimes for SiNWs with ⟨100⟩ and ⟨111⟩ growth directions. Specifically, we account for nonradiative transitions between electronic states with different momentum, where changes in energy and momentum are achieved via interaction with a thermal bath of nuclear degrees of freedom. Photoexcited dynamic processes in reference SiNWs are computed via “on-the-fly” nonadiabatic couplings between electronic and nuclear degrees of freedom based on density functional theory (DFT). The dynamics of electronic degrees of freedom is propagated by a Redfield equation of motion for the reduced density matrix. Our results show that transitions allowing change of momentum prompt electron relaxation faster than those not allowing change of momentum. Our study also indicates that the electron relaxation time in ⟨100⟩ SiNW is longer than that in ⟨111⟩ SiNW.

Authors:
 [1]; ORCiD logo [1];  [1];  [2];  [3]; ORCiD logo [4]; ORCiD logo [1]
  1. Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108, United States
  2. Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk 630090, Russian Federation; National University of Science and Technology MISIS, 4 Leninskiy pr., Moscow 119049, Russian Federation; L. N. Gumilyov Eurasian National University, Astana 010008, Kazakhstan
  3. Department of Physics &, Astrophysics, University of North Dakota, Grand Forks, North Dakota 58202, United States
  4. Department of Physics, North Dakota State University, Fargo, North Dakota 58102, United States
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory-National Energy Research Scientific Computing Center (NERSC)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1529965
DOE Contract Number:  
AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 123; Journal Issue: 12; Journal ID: ISSN 1932-7447
Country of Publication:
United States
Language:
English

Citation Formats

Fatima, N/A, Han, Yulun, Vogel, Dayton J., Inerbaev, Talgat M., Oncel, Nuri, Hobbie, Erik K., and Kilin, Dmitri S. Photoexcited Electron Lifetimes Influenced by Momentum Dispersion in Silicon Nanowires. United States: N. p., 2019. Web. doi:10.1021/acs.jpcc.9b00639.
Fatima, N/A, Han, Yulun, Vogel, Dayton J., Inerbaev, Talgat M., Oncel, Nuri, Hobbie, Erik K., & Kilin, Dmitri S. Photoexcited Electron Lifetimes Influenced by Momentum Dispersion in Silicon Nanowires. United States. doi:10.1021/acs.jpcc.9b00639.
Fatima, N/A, Han, Yulun, Vogel, Dayton J., Inerbaev, Talgat M., Oncel, Nuri, Hobbie, Erik K., and Kilin, Dmitri S. Wed . "Photoexcited Electron Lifetimes Influenced by Momentum Dispersion in Silicon Nanowires". United States. doi:10.1021/acs.jpcc.9b00639.
@article{osti_1529965,
title = {Photoexcited Electron Lifetimes Influenced by Momentum Dispersion in Silicon Nanowires},
author = {Fatima, N/A and Han, Yulun and Vogel, Dayton J. and Inerbaev, Talgat M. and Oncel, Nuri and Hobbie, Erik K. and Kilin, Dmitri S.},
abstractNote = {Silicon nanowires (SiNWs) exhibit unique optoelectronic properties originating from one-dimensional confinement effect. Technologically relevant properties—including band gap, radiative and nonradiative transitions, and charge carrier relaxation rates—are influenced by sampling of momentum along the growth direction. In this work, we quantify the influence of momentum dispersion on hot-electron relaxation rates and nonradiative lifetimes for SiNWs with ⟨100⟩ and ⟨111⟩ growth directions. Specifically, we account for nonradiative transitions between electronic states with different momentum, where changes in energy and momentum are achieved via interaction with a thermal bath of nuclear degrees of freedom. Photoexcited dynamic processes in reference SiNWs are computed via “on-the-fly” nonadiabatic couplings between electronic and nuclear degrees of freedom based on density functional theory (DFT). The dynamics of electronic degrees of freedom is propagated by a Redfield equation of motion for the reduced density matrix. Our results show that transitions allowing change of momentum prompt electron relaxation faster than those not allowing change of momentum. Our study also indicates that the electron relaxation time in ⟨100⟩ SiNW is longer than that in ⟨111⟩ SiNW.},
doi = {10.1021/acs.jpcc.9b00639},
journal = {Journal of Physical Chemistry. C},
issn = {1932-7447},
number = 12,
volume = 123,
place = {United States},
year = {2019},
month = {1}
}