Theses and Dissertations

Hao Chang

Issuing Body

Mississippi State University

Advisor

Gwaltney, Steven R.

Committee Member

Scott, Colleen N.

Committee Member

Wipf, David O.

Date of Degree

5-3-2019

Original embargo terms

Visible to MSU only for 3 years

Document Type

Graduate Thesis - Open Access

Major

Chemistry

Degree Name

Master of Science (M.S.)

College

College of Arts and Sciences

College

College of Arts and Sciences

Department

Department of Chemistry

Department

Department of Chemistry

Abstract

Organic photovoltaic cells (OPV’s), renewable energy devices that can convert sunlight into electricity, have a bright future. Most OPV’s are made of conjugated polymers since they can absorb light and have semiconducting properties. However, the low power conversion efficiency (PCE) of OPV’s is a challenge in their development. The main structure of OPV’s includes three main parts: an electron donor, an electron acceptor, and electrodes. To improve the PCE of an OPV, many factors need to be considered, such as light absorption, the fundamental gap, the optical gap, and the OPV’s film thickness. The addition of heteroatoms to conjugated polymers is a way to change the electronic properties of the donors and may improve the PCE. This thesis describes the use of computational methods to determine how oxygen and sulfur atoms affect the electronic properties of a conjugated polymer. The data suggest that the fundamental gaps and binding energies decrease after replacing oxygen with sulfur. Additionally, the results also suggest that incorporating a sulfur atom into the conjugated polymer can increase the dipole moment change, which may lead to accelerated charge dissociation and may reduce charge recombination.

URI

https://hdl.handle.net/11668/21249

Comments

conjugated polymer||energy gap

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