Session:

Through a decade of intensive research and development, over 25% of power conversion efficiency has been achieved in perovskite solar cells, placing it in direct competition with silicon-based solar cells. Further improvement toward theoretical limits relies on a better understanding of the charge dynamics in the device under operational conditions. Charge carrier recombination and extraction rates are key parameters that directly define the device performance. However, there are notable variations among the values reported for the device made with the same material and device stacks. Here, we study the charge extraction and recombination dynamics in perovskite solar cells based on the most common compositions, including prototypical methylammonium lead iodide (MAPI₃), formamidinium (FA)-cesium lead iodide (FA_0.95Cs_0.05PbI₃), triple-cation lead halide ([(FAPbI₃)_0.87(MAPbBr₃)_0.13]_0.92[CsPbI₃]_0.08), and mixed tin-lead iodide (FA_0.7MA_0.3Sn_0.5Pb_0.5I₃) perovskites via transient photovoltage and photocurrent (TPV/TPC) techniques under various illumination intensities and light soaking conditions. We also investigated the effect of a hole transporting layer (Spiro-OMeTAD derivative referred to as HTM3) on MAPI₃-based devices under the same experimental conditions. We found that the TPV and TPC traces vary significantly with light soaking in terms of TPV/TPC amplitudes and lifetimes of the fast and slow components, depending on both perovskite and HTM. On the triple-cation lead halide perovskite-based device, the effect occurs on the TPC, while on the MAPI₃-based device with HTM3, it appears on the TPV. Careful analysis of the data, including the reproduction of short-circuit current densities and open-circuit voltages of each device measured at various light intensities using the parameters extracted from TPV/TPC, revealed that the variation in TPV/TPC of the light-soaked devices relates to the changes in perovskite composition and perovskite-HTM interface.

Co-Author(s): Agustin Ontoria (Imdea Nanociencia), Zhaoning Song (University of Toledo), Iwan zimmerm (EPFL VALAIS), Jose Santos (Imdea Nanociencia), Juan Cabanillas (Imdea Nanociencia), Nijiati Aimaiti (Imdea Nanociencia), Manoj Rajakaruna (University of Toledo), You Li (University of Toledo), Lei Chen (University of Toledo), Sheng Fu (University of Toledo), Adam Phillips (University of Toledo), Michael Heben (University of Toledo), Mohammad Nazeeruddin (EPFL VALAIS), Nazario Leon (Universidad Complutense de Madrid), Yanfa Yan (University of Toledo), Randy Ellingson (University of Toledo)

Abasi Abudulimu

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