The work presented here is the first of its kind where nanocrystal-based photovoltaics are characterized by directly imaging the electronic properties and correlating them to the structure of the sample. Through electron beam-induced current (EBIC), a finite beam of high energy electrons mimics photons to generate a photoresponse in the device, thus enabling the measurement of the current being generated in a precise region of the specimen. Two different nanocrystal-based architectures were studied in this manner: (1) a hybrid bulk heterojunction composed of CdSe nanorods dispersed in a conductive polymer matrix and (2) a PbS quantum dot depleted-heterojunction device. Both yielded significant results, such as high hole mobility in the case of (1), and changes in the EBIC signature as a result of defects in (2); the electronic shortcomings of the devices believed prior to this work were also confirmed. Another PbS quantum dot-based device was characterized using high resolution elemental mapping; this architecture comprised of titania nanotubes rather than nanoparticles as used in the photovoltaic described in (2). Preliminary work on CdTe thin film solar cells was also conducted as a test bed for higher resolution EBIC.
With EBIC, maps of nanocrystal-based, solid state photovoltaics were collected and analyzed to reveal important information regarding the electronic properties of the devices as well as areas of improvement. As a result of the latter, more efficient solar cell technology can be developed to help meet the energy demands of the global population.
| Identifer | oai:union.ndltd.org:VANDERBILT/oai:VANDERBILTETD:etd-12112014-141358 |
| Date | 22 December 2014 |
| Creators | Ng, Amy |
| Contributors | Sandra J. Rosenthal, Stephen J. Pennycook, David E. Cliffel, Charles M. Lukehart |
| Publisher | VANDERBILT |
| Source Sets | Vanderbilt University Theses |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.vanderbilt.edu/available/etd-12112014-141358/ |
| Rights | restrictone, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Vanderbilt University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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