Chemistry and Chemical Biology ETDs

Publication Date

Spring 4-15-2019

Abstract

The current state of organic photovoltaics is centered on systems of polymeric donors and some type of acceptor molecule (i.e. fullerene) formed into an active layer that adopts a bulk-heterojunction morphology. Although these devices have come a far way from where they were when they were first discovered in the 1980’s much work is still needed to make them a viable technology. Two of the limitations of this type of devices revolve around the relatively narrow absorption window of the components and lack of control over the morphology after the film is cast. To overcome these shortcomings there are several strategies that have been developed.

In this dissertation, the use of a complementary absorber will be used to try and overcome the narrow absorption window of the active layer. The complementary absorber that will be used is the quantum dot. This class of material was selected because of their simple synthesis, tunable absorption window and the ease of modification through alteration of the ligand shell. To gain better control over the morphology, the polymeric donor material P3HT and a P3HT based block copolymer will be formed into nanofibers. To achieve even more control over the morphology, a core-shell system will be introduced based on a core of polymeric nanofibers and a shell of quantum dots. Also, this core-shell architecture will promote a cascade type mechanism of charge transport among the three components of the active layer. To ensure this orthogonal non-covalent bonding will be introduced to tether the quantum dots and polymer together. To achieve this non-covalent bonding regime between quantum dot and polymer, both will need to be modified. The ligand shell of the quantum dot will be engineered to introduce a moiety that will interact with a modification to the side chain of the P3HT base polymer. This interaction will be designed to be a pi-pi type of interaction. Although the application of this complementary absorbing species drastically affected the performance of OPV devices in a negative sense, this study did demonstrate that quantum dots can be coordinated to the nanofiber.

Language

English

Keywords

P3HT, Organic Photovoltaic, Ternary Blend, Quantum dots, CdSe

Document Type

Dissertation

Degree Name

Chemistry

Level of Degree

Doctoral

Department Name

Department of Chemistry and Chemical Biology

First Committee Member (Chair)

Yang Qin

Second Committee Member

Yi He

Third Committee Member

Ramesh Giri

Fourth Committee Member

Song Eon Han

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re upload with the format fixed

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