Relation between charge carrier mobility and lifetime in organic photovoltaics

Vijila C., Singh S.P., Williams E., Sonar P., Pivrikas A., Philippa B., White R., Naveen Kumar E., Gomathy Sandhya S., Gorelik S., Hobley J., Furube A., Matsuzaki H. and Katoh R. (2013) Relation between charge carrier mobility and lifetime in organic photovoltaics. Journal of Applied Physics, 114 18: 184503-1-184503-6. doi:10.1063/1.4829456


Author Vijila C.
Singh S.P.
Williams E.
Sonar P.
Pivrikas A.
Philippa B.
White R.
Naveen Kumar E.
Gomathy Sandhya S.
Gorelik S.
Hobley J.
Furube A.
Matsuzaki H.
Katoh R.
Title Relation between charge carrier mobility and lifetime in organic photovoltaics
Journal name Journal of Applied Physics   Check publisher's open access policy
ISSN 0021-8979
1089-7550
Publication date 2013-11-14
Year available 2013
Sub-type Article (original research)
DOI 10.1063/1.4829456
Open Access Status DOI
Volume 114
Issue 18
Start page 184503-1
End page 184503-6
Total pages 6
Place of publication College Park, United States
Publisher American Institute of Physics
Collection year 2014
Language eng
Abstract The relationship between charge carrier lifetime and mobility in a bulk heterojunction based organic solar cell, utilizing diketopyrrolopyrole- naphthalene co-polymer and PC71BM in the photoactive blend layer, is investigated using the photoinduced charge extraction by linearly increasing voltage technique. Light intensity, delay time, and temperature dependent experiments are used to quantify the charge carrier mobility and density as well as the temperature dependence of both. From the saturation of photoinduced current at high laser intensities, it is shown that Langevin-type bimolecular recombination is present in the studied system. The charge carrier lifetime, especially in Langevin systems, is discussed to be an ambiguous and unreliable parameter to determine the performance of organic solar cells, because of the dependence of charge carrier lifetime on charge carrier density, mobility, and type of recombination. It is revealed that the relation between charge mobility (μ) and lifetime (τ) is inversely proportional, where the μτ product is independent of temperature. The results indicate that in photovoltaic systems with Langevin type bimolecular recombination, the strategies to increase the charge lifetime might not be beneficial because of an accompanying reduction in charge carrier mobility. Instead, the focus on non-Langevin mechanisms of recombination is crucial, because this allows an increase in the charge extraction rate by improving the carrier lifetime, density, and mobility simultaneously.
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Centre for Organic Photonics and Electronics
Official 2014 Collection
 
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