Mapping the Competition between Exciton Dissociation and Charge Transport in Organic Solar Cells
- Authors
- Oh, Soong Ju; Kim, Jongbok; Mativetsky, Jeffrey M.; Loo, Yueh-Lin; Kagan, Cherie R.
- Issue Date
- 26-Oct-2016
- Publisher
- AMER CHEMICAL SOC
- Keywords
- organic solar cells; charge transport; exciton dissociation; scanning confocal photoluminescence microscopy; scanning photocurrent microscopy
- Citation
- ACS APPLIED MATERIALS & INTERFACES, v.8, no.42, pp.28743 - 28749
- Journal Title
- ACS APPLIED MATERIALS & INTERFACES
- Volume
- 8
- Number
- 42
- Start Page
- 28743
- End Page
- 28749
- URI
- https://scholarworks.bwise.kr/kumoh/handle/2020.sw.kumoh/1182
- DOI
- 10.1021/acsami.6b07810
- ISSN
- 1944-8244
- Abstract
- The competition between exciton dissociation and charge transport in organic solar cells comprising poly(3-hexylthiophene) [P3HT] and phenyl-C61-butyric acid methyl ester [PCBM] is investigated by correlated scanning confocal photoluminescence and photocurrent microscopies. Contrary to the general expectation that higher photoluminescence quenching is indicative of higher photocurrent, microscale mapping of bulk-heterojunction solar-cell devices shows that photoluminescence quenching and photocurrent can be inversely proportional to one another. To understand this phenomenon, we construct a model system by selectively laminating a PCBM layer onto a P3HT film to form a PCBM/P3HT planar junction on half of the device and a P3HT single junction on the other half. Upon thermal annealing to allow for interdiffusion of PCBM into P3HT, an inverse relationship between photoluminescence quenching and photocurrent is observed at the boundary between the PCBM/P3HT junction and P3HT layer. Incorporation of PCBM in P3HT works to increase photoluminescence quenching, consistent with efficient charge separation, but conductive atomic force microscopy measurements reveal that PCBM acts to decrease P3HT hole mobility, limiting the efficiency of charge transport. This suggests that photoluminescence-quenching measurements should be used with caution in evaluating new organic materials for organic solar cells.
- Files in This Item
- There are no files associated with this item.
- Appears in
Collections - Department of Materials Science and Engineering > 1. Journal Articles
Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.