Direct and charge transfer mediated photogeneration in polymer-fullerene bulk heterojunction solar cells

Abstract

We investigated photogeneration yield and recombination dynamics in blends of poly(3-hexyl thiophene) (P3HT) and poly[2-methoxy-5-(30,70-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) with [6,6]- phenyl-C61 butyric acid methyl ester (PC61BM) by means of temperature dependent time delayed collection field (TDCF) measurements. In MDMO-PPV:PC61BM we find a strongly field dependent polaron pair dissociation which can be attributed to geminate recombination in the device. Our findings are in good agreement with field dependent photoluminescence measurements published before, supporting a scenario of polaron pair dissociation via an intermediate charge transfer (CT) state. In contrast, polaron pair dissociation in P3HT:PC61BM shows only a very weak field dependence, indicating an almost field independent polaron pair dissociation or a direct photogeneration. Furthermore, we found Langevin recombination for MDMO-PPV:PC61BM and strongly reduced Langevin recombination for P3HT:PC61BM.

arXiv comment4 pages, 3 figures

References in corpus (7)

• The Role of Driving Energy and Delocalised States for Charge Separation in Organic Semiconductors
• Polymer-Fullerene Bulk Heterojunction Solar Cells
• Origin of Reduced Polaron Recombination in Organic Semiconductor Devices
• Triplet Exciton Generation in Bulk-Heterojunction Solar Cells based on Endohedral Fullerenes
• Investigation of the Photocurrent in Bulk Heterojunction Solar Cells
• Bipolar Charge Transport in Poly(3-hexyl thiophene)/Methanofullerene Blends: A Ratio Dependent Study
• Binding energy of singlet excitons and charge transfer complexes in MDMO-PPV:PCBM solar cells

Cited by in corpus (8)

• Nongeminate and Geminate Recombination in PTB7:PC${}_{71}$BM solar cells
• Charge-Transfer State Dynamics Following Hole and Electron Transfer in Organic Photovoltaic Devices
• Shockley Equation Parameters of Organic Solar Cells derived by Transient Techniques
• Nongeminate recombination in neat P3HT and P3HT:PCBM blend films
• Impact of a doping-induced space-charge region on the collection of photo-generated charge carriers in thin-film solar cells based on low-mobility semiconductors
• Multiscale Modeling and Simulation of Organic Solar Cells
• Impact of nongeminate recombination on the performance of pristine and annealed P3HT:PCBM solar cells
• Reduced Coulomb interaction in organic solar cells by the introduction of inorganic high-k nanostructured materials