2009/07/14 by Carsten Deibel, C. Deibel, A. Wagenpfahl +3 · 1 citation
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Anode #Atomic physics #Cathode #Charge carrier #Chemical physics #Chemistry #Conducting polymers and applications #Electrode #Electron #Materials science #Molecular physics #Optoelectronics #Organic Electronics and Photovoltaics #Organic semiconductor #Organic solar cell #Perovskite Materials and Applications #Physical chemistry #Physics #Polaron #Polymer #Polymer solar cell #Recombination #Recombination rate #Semiconductor #Solar cell #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.80.075203
published as Phys. Rev. B 80, 075203 (2009) · 7 pages, 6 figures
arxiv created 2009/07/14 · openalex publication_date 2009/08/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We propose a model to explain the reduced bimolecular recombination rate found in state-of-the-art bulk heterojunction solar cells. When compared to the Langevin recombination, the experimentally observed rate is one to four orders of magnitude lower but gets closer to the Langevin case for low temperatures. Our model considers the organic solar cell as device with carrier-concentration gradients, which form due to the electrode/blend/electrode device configuration. The resulting electron concentration under working conditions of a solar cell is higher at the cathode than at the anode and vice versa for holes. Therefore, the spatially dependent bimolecular recombination rate, proportional to the local product of electron and hole concentrations, is much lower as compared to the calculation of the recombination rate based on the extracted and thus averaged charge-carrier concentrations. We consider also the temperature dependence of the recombination rate, which can be described with our model.