Insight into the energy loss in organic solar cells based on benzotrithiophene copolymers: A dark current analysis at low temperature
Abstract
<jats:title>Abstract</jats:title> <jats:p>Owing to the formation of the charge transfer (CT) state, the open-circuit voltage (<jats:italic>V</jats:italic> <jats:sub>oc</jats:sub>) of organic photovoltaic (OPV) devices commonly suffers an energy loss of 0.8–1.3 eV from the effective bandgap. Benzotrithiophene (BTT)-based low-bandgap polymers that we have recently reported showed deep HOMO levels (−5.4 to −5.6 eV) and moderate optical bandgaps of 1.7–1.8 eV, which resulted in high <jats:italic>V</jats:italic> <jats:sub>oc</jats:sub>’s of 0.78–0.98 V and relatively low energy losses when blended with methano[60]fullerene (PCBM). Here, we report the temperature-dependent dark current analysis of organic solar cells of BTT copolymers:PCBM blends. Shockley diode analyses revealed the dominant contribution of CT energy and concomitant pre-exponential factor of dark saturation current density associated with charge recombination. The findings could establish a fundamental aspect to draw a design rule in BTT-based polymers towards their evolutions in OPV devices.</jats:p>
Journal
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- Japanese Journal of Applied Physics
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Japanese Journal of Applied Physics 55 (2), 022303-, 2016-01-15
IOP Publishing
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Details 詳細情報について
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- CRID
- 1360566399843730304
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- NII Article ID
- 210000146025
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- ISSN
- 13474065
- 00214922
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- Data Source
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- Crossref
- CiNii Articles
- KAKEN