In this dissertation, I present the results of my research on a prototypical interface of the metal oxide ZnO and the organic semiconductor C₆₀. I establish that the physics at such oxide / organic interfaces is complex and very different from the extensively investigated case of organic semiconductor / metal interfaces. The studies presented in this dissertation were designed to address and improve the understanding of the fundamental physics at such hybrid organic / inorganic interfaces. Using photoemission spectroscopies, I show that metal oxide defect states play an important role in determining the interfacial electronic properties, such as energy level alignment and charge carrier dynamics. In particular, I show that for hybrid interfaces, electronic phenomena are sensitive to the surface electronic structure of the inorganic semiconductor. I also demonstrate applications of photoemission spectroscopies which are unique in that they allow for a direct comparison of ultrafast charge carrier dynamics at the interface and the electronic structure of defect levels. The research presented here focuses on a achieving a significant understanding of the realistic and device relevant C₆₀ / ZnO hybrid interface. I show how the complex surface structure of ZnO can be modified by simple experimental protocols, with direct and dramatic consequences on the interfacial energy level alignment, carrier dynamics and carrier collection and injection efficiencies. As a result of this careful study of the electronic structure and dynamics at the C₆₀ / ZnO interface, a greater understanding of the role of gap states in interface hybridization and charge carrier localization is obtained. This dissertation constitutes a first step in achieving a fundamental understanding of hybrid interfacial electronic properties.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/566997 |
| Date | January 2015 |
| Creators | Kelly, Leah L. |
| Contributors | Monti, Oliver L. A., Brown, Michael F., Armstrong, Neal R., Sanov, Andrei, Monti, Oliver L. A. |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Electronic Dissertation |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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