Dresden 2017 – wissenschaftliches Programm
CPP 13.28: Poster
Montag, 20. März 2017, 18:30–21:00, P1A
Origin and Location of Trap States in Perovskite Films — •Tobias Seewald1, Carola Ebenhoch1, Philipp Ehrenreich1, Rebecca Milot2, Susanne Birkhold1, Laura Herz2, and Lukas Schmidt-Mende1 — 1Department of Physics, University of Konstanz, POB M 680, Konstanz 78457, Germany — 2University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK
Lead halide perovskites have experienced tremendous research interest within the last years. High power conversion efficiencies in combination with the ability of crystal formation during a solution casting process make this material class very attractive for photovoltaic application. For efficient charge carrier generation, it is essential to minimize non-radiative recombination that can be initiated by energetic trap states. For this purpose, we have studied polycrystalline methylammonium lead iodide perovskite films with varying crystal sizes. Morphology and crystallinity have been modified by means of methylamine gas induced defect healing. Time-resolved photoluminescence as well as pump-probe spectroscopy have been applied in order to relate trap state distribution with crystal sizes and grain boundaries. In this study we can demonstrate the importance of large crystal grains, which allow for high carrier mobilities and reduced non-radiative losses that are crucial for efficient solar cell devices.