Impact of Residual Lead Iodide on Photophysical Properties of Lead Triiodide Perovskite Solar Cells
AuthorsKhan, Jafar Iqbal
Sheikh, Arif D.
Alamoudi, Maha A
KAUST DepartmentKAUST Solar Center (KSC)
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Permanent link to this recordhttp://hdl.handle.net/10754/660539
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AbstractThe role of residual lead iodide on the photophysical properties of methylammonium lead iodide is still unclear and contradictory views exist about its impact. Herein, it is reported that there is a critical amount of residual lead iodide, which is beneficial for the solar cell performance. Transient absorption spectroscopy is used to investigate the charge carrier recombination dynamics in perovskite solar cells and to address the role of different amounts of residual lead iodide. The amount of lead iodide is varied through the perovskite thin film preparation protocol upon a modified two-step fabrication process. Slower carrier dynamics are observed at the perovskite/titanium dioxide interface in the presence of residual lead iodide when exciting the perovskite at the perovskite/titanium interface, which correlates with improved solar cell device performance. Excitation from the perovskite side indicates that the effect of residual lead iodide is primarily at the titanium dioxide interface. Increasing the lead iodide content does not further alter the carrier recombination; on the contrary, it results in lower device performance. This study confirms that the presence of lead iodide can have a beneficial effect, as it reduces charge carrier recombination at the perovskite/titanium dioxide interface.
CitationKhan, J. I., Sheikh, A. D., Alamoudi, M. A., Barrit, D., Ugur, E., Laquai, F., & Amassian, A. (2019). Impact of Residual Lead Iodide on Photophysical Properties of Lead Triiodide Perovskite Solar Cells. Energy Technology, 1900627. doi:10.1002/ente.201900627
SponsorsJ.I.K. and A.D.S. contributed equally to this work. This publication is based upon work supported by the King Abdullah University of Science and Technology (KAUST), Office of Sponsored Research (OSR) under Award No: OSR-2018-CARF/CCF-3079.