Charge recombination in organic small-molecule solar cells by Jiye Lee.

To enhance the power conversion efficiency in organic solar cells, charge recombination loss needs to be minimized. First, we perform transient absorption spectroscopy to study the charge recombination dynamics of thin film bulk heterojunction of the archetype organic solar cell molecules, copper phthalocyanine (CuPC) and 3,4,9,10-perylenetetracarboxylic bis-benzimidazole (PTCBI). We report the formation of triplet excitons on PTCBI molecules, which may be an important source of recombination loss in CuPC/PTCBI photovoltaic cells. Second, spin-forbidden transition can be employed to reduce the recombination loss in organic solar cells. We show with a simulation that the spin-disallowed recombination process increases the charge collection efficiency. Also, we present an experimental result that may imply the spin-dependent open-circuit voltage in organic bilayer photovoltaic devices.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2008

Author dc:creator

• Lee, Jiye

Advisor dc:contributor.advisor

• Marc A. Baldo.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/45829

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/45829