High field magneto-photocurrent in organic bulk hetero-junction photo-voltaic cells

• Published in: Synthetic metals 2015-10, Vol.208, p.49-52
• Main Authors: Khachatryan, B., Devir-Wolfman, A.H., Tzabary, L., Keren, A., Tessler, N., Vardeny, Z.V., Ehrenfreund, E.
• Format: Article
• Language: English
• Subjects: Charge transfer; Decomposition; Excitons; Magneto-photoconductanc; Organic photovoltaic cell; Photovoltaic cells; Solar cells; Synthetic metals; Time domain
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2015.05.008

[Display omitted] •rrP3HT/PCBM bulk hetero-junction photo-voltaic cell produced photocurrent (PC) upon 470nm LED irradiation.•The resulting photocurrent were studied using high (up to 8.5T) magnetic field (MPC).•The observed high field MPC is attributed to a spin-mixing mechanism caused by the difference in the donor-acceptor g-factors.•The non-saturating MPC response at high field is interpreted as due to charge transfer excitons with in the sub-nanosecond lifetime.•The MPC response profile is highly non-Lorentzian due to a dispersive decay mechanism. We analyze the high field (up to 8.5T) non-saturating magneto-photocurrent (MPC) in rrP3HT/PCBM bulk hetero-junction photo-voltaic cells. We attribute the observed high field MPC at room temperature to a spin-mixing mechanism caused by the difference in the donor-acceptor g-factors. The non-saturating MPC response at high field indicates that there exist charge transfer excitons with lifetime in the sub-nanosecond time domain. The MPC response profile is highly non-Lorentzian. We explain this non-Lorentzian shape by a dispersive decay mechanism that originates due to a broad distribution of charge transfer exciton lifetimes.