From growth to TR-ARPES of C₆₀ : a prototypical OPV system
department or school: Science, Faculty of
department or school: Physics and Astronomy, Department of
data provider: DSpace
degree campus: UBCV
creator: Tully, Alexandra Bennett
issued: 2024-01-02T19:24:11Z
issued: 2023
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Organic photovoltaics (OPVs) have the potential to serve as flexible and transparent solar cells, comprised of inexpensive materials and created through scalable and energy efficient processes. However, poor power conversion efficiency (largely due to inefficient charge separation) prevents them from being a commercial competitor to today’s conventional solar cells. This thesis marks the first results of a collaborative research project at the University of British Columbia’s Stewart Blusson Quantum Matter Institute investigating the physics underlying poor charge transfer in OPVs. The first step in engineering more efficient charge separation is understanding the fundamentals of the charge transfer process. When an electron is excited in an OPV, it remains coulombically bound with its hole, forming an exciton. Excitons in organic solar cells are more tightly bound with larger binding energies than those in conventional solar cells, making them harder to dissociate into free charges. The nature of these excitons plays a role in the generation of free carriers in OPVs, but it remains an open question that can benefit from the temporal and spatial information provided by time- and angle-resolved photoemission spectroscopy (TR-ARPES). We work with neat C60 thin films due to the material’s foundational status as a prototypical OPV electron-acceptor material and because it is a photo-absorbing excitonic semiconductor, with a manifold of optically-accessible excitonic states. The importance of long-range order to conducting spectroscopic analysis of a thin film’s electronic structure prompted our development of a generalizable growth technique that consistently results in single-domain C60 films of controllable thicknesses, using Au(111) as an epitaxially well-matched substrate. To better understand the evolution of the optically-excited carriers, we use TR-ARPES (supported by low-energy electron diffraction and scanning tunneling microscopy) to investigate and to map the…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/87013
note: From Growth to TR-ARPES of C60:a Prototypical OPV SystembyAlexandra Bennett TullyB.Sc., Yale University, 2014M.Sc., The University of British Columbia, 2019A THESIS SUBMITTED IN PARTIAL FULFILLMENT OFTHE REQUIREMENTS FOR THE DEGREE OFDOCTOR OF PHILOSOPHYinThe Faculty of Graduate and Postdoctoral Studies(Physics)THE UNIVERSITY OF BRITISH COLUMBIA(Vancouver)December 2023© Alexandra Bennett Tully 2023The following individuals certify that they have read, and recommend tothe Faculty of Graduate and Postdoctoral Studies for acceptance, the thesisentitled:From Growth to TR-ARPES of C60:a Prototypical OPV Systemsubmitted by Alexandra Bennett Tully in partial fulfillment of therequirements for the degree of Doctor of Philosophy in Physics.Examining Committee:Sarah Burke, Associate Professor, Physics and Astronomy, Chemistry, UBCSupervisorDavid Jones, Professor, Physics and Astronomy, UBCCo-supervisorCarlos Silva-Acun˜a, Professor, Physics, Universite´ de Montre´alExternal ExaminerTakamasa Momose, Professor, Chemistry, UBCUniversity ExaminerAlireza Nojeh, Professor, Electrical and Computer Engineering, UBCUniversity ExaminerMona Berciu, Professor, Physics and Astronomy, UBCSupervisory Committee MemberAdditional Supervisory Committee Members:Jeremy Heyl, Professor, Physics and Astronomy, UBCSupervisory Committee MemberiiAbstractOrganic photovoltaics (OPVs) have the potential to serve as flexible and trans-parent solar cells, comprised of inexpensive materials and created throughscalable and energy efficient processes. However, poor power conversionefficiency (largely due to inefficient charge separation) prevents them frombeing a commercial competitor to today’s conventional solar cells. This thesismarks the first results of a collaborative research project at the University ofBritish Columbia’s Stewart Blusson Quantum Matter Institute investigatingthe physics underlying poor charge transfer in OPVs.The first step in engineering more efficient charge separation is under-stand…
has type: Thesis/Dissertation
date issued: 2024-05
is shown at: 10.14288/1.0438374
language: eng
degree discipline: Physics
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Burke, Sarah A.
contributor: Jones, David John, 1969-
type: Text
identifier URI: http://hdl.handle.net/2429/87013