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Title: Why the apparent order of bimolecular recombination in blend organic solar cells can be larger than two: A topological consideration

Abstract

The apparent order δ of non-geminate recombination higher than δ = 2 has been evidenced in numerous experiments on organic bulk heterojunction (BHJ) structures intensively studied for photovoltaic applications. This feature is claimed puzzling, since the rate of the bimolecular recombination in organic BHJ systems is proportional to the product of the concentrations of recombining electrons and holes and therefore the reaction order δ = 2 is expected. In organic BHJ structures, electrons and holes are confined to two different material phases: electrons to the acceptor material (usually a fullerene derivative) while holes to the donor phase (usually a polymer). The non-geminate recombination of charge carriers can therefore happen only at the interfaces between the two phases. Considering a simple geometrical model of the BHJ system, we show that the apparent order of recombination can deviate from δ = 2 due solely to the topological structure of the system.

Authors:
;  [1];  [2]; ; ; ;  [3]
  1. Institute of Semiconductor Physics, 630090 Novosibirsk (Russian Federation)
  2. (Russian Federation)
  3. Department of Physics and Material Sciences Center, Philipps-University, D-35032 Marburg (Germany)
Publication Date:
OSTI Identifier:
22594480
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CHARGE CARRIERS; CONCENTRATION RATIO; ELECTRONS; FULLERENES; HETEROJUNCTIONS; HOLES; INTERFACES; ORGANIC SOLAR CELLS; PHOTOVOLTAIC EFFECT; POLYMERS; RECOMBINATION; TOPOLOGY

Citation Formats

Nenashev, A. V., Dvurechenskii, A. V., Novosibirsk State University, 630090 Novosibirsk, Wiemer, M., Gebhard, F., Koch, M., and Baranovskii, S. D. Why the apparent order of bimolecular recombination in blend organic solar cells can be larger than two: A topological consideration. United States: N. p., 2016. Web. doi:10.1063/1.4959076.
Nenashev, A. V., Dvurechenskii, A. V., Novosibirsk State University, 630090 Novosibirsk, Wiemer, M., Gebhard, F., Koch, M., & Baranovskii, S. D. Why the apparent order of bimolecular recombination in blend organic solar cells can be larger than two: A topological consideration. United States. doi:10.1063/1.4959076.
Nenashev, A. V., Dvurechenskii, A. V., Novosibirsk State University, 630090 Novosibirsk, Wiemer, M., Gebhard, F., Koch, M., and Baranovskii, S. D. Mon . "Why the apparent order of bimolecular recombination in blend organic solar cells can be larger than two: A topological consideration". United States. doi:10.1063/1.4959076.
@article{osti_22594480,
title = {Why the apparent order of bimolecular recombination in blend organic solar cells can be larger than two: A topological consideration},
author = {Nenashev, A. V. and Dvurechenskii, A. V. and Novosibirsk State University, 630090 Novosibirsk and Wiemer, M. and Gebhard, F. and Koch, M. and Baranovskii, S. D.},
abstractNote = {The apparent order δ of non-geminate recombination higher than δ = 2 has been evidenced in numerous experiments on organic bulk heterojunction (BHJ) structures intensively studied for photovoltaic applications. This feature is claimed puzzling, since the rate of the bimolecular recombination in organic BHJ systems is proportional to the product of the concentrations of recombining electrons and holes and therefore the reaction order δ = 2 is expected. In organic BHJ structures, electrons and holes are confined to two different material phases: electrons to the acceptor material (usually a fullerene derivative) while holes to the donor phase (usually a polymer). The non-geminate recombination of charge carriers can therefore happen only at the interfaces between the two phases. Considering a simple geometrical model of the BHJ system, we show that the apparent order of recombination can deviate from δ = 2 due solely to the topological structure of the system.},
doi = {10.1063/1.4959076},
journal = {Applied Physics Letters},
number = 3,
volume = 109,
place = {United States},
year = {Mon Jul 18 00:00:00 EDT 2016},
month = {Mon Jul 18 00:00:00 EDT 2016}
}