Date of Award
2020
Publisher
North Dakota State University
Document Type
Thesis
Degree Awarded
Master of Science (MS)
Program
Physics
Department
Physics
College
Science and Mathematics
Faculty Advisor
Kryjevski, Andrei
Description
We analyze a toy model for p-n junction photovoltaic devices by simulating photoexcited state dynamics in silicon nanowires. One nanowire is approximately circular in cross section with a diameter of d = 1.17 nm. The other has an approximately rhombic cross-section with d1 = 1.16 nm and d2 = 1.71 nm. Both nanowires have been doped with aluminum and phosphorus atoms and capped with gold leads. We use Boltzmann transport equation (BE) that includes phonon emission, carrier multiplication (CM), and exciton transfer. BE rates are computed using non-equilibrium finite-temperature many-body perturbation theory (MBPT) based on Density Functional Theory (DFT) simulations, including excitonic effects from Bethe-Salpeter Equation. We compute total charge transfer amount generated from the initial photoexcitation and find an enhancement when CM is included. In particular, we see between 78% and 79% enhancement in the smaller wire, while we see 116% enhancement in the larger nanowire
Recommended Citation
Walker, Nathan Thomas, "A Density Functional Theory and Many Body Perturbation Theory Based Study of Photo-Excited Charge Separation in Doped Silicon Nanowires with Gold Leads: Toy Models for the Photovoltaic Effect" (2020). Physics. 15.
https://digitalcommons.ndsu.edu/physics/15
Rights
NDSU policy 190.6.2
Rights Link
https://www.ndsu.edu/fileadmin/policy/190.pdf
Handle Identifier
https://hdl.handle.net/10365/31785