Dresden 2017 – wissenschaftliches Programm
CPP 13.10: Poster
Montag, 20. März 2017, 18:30–21:00, P1A
Impact of additional PbI2 and the grain size on optical properties in hybrid lead halide perovskites — •Tobias Meier1, Fabian Panzer1,2,3, Tanaji Gujar4, Mukundan Thelakkat4, and Anna Köhler1,2 — 1Experimental Physics II — 2Bayreuth Institute of Macromolecular Research (BIMF) — 3Department of Functional Materials — 4Applied Functional Polymers, Macromolecular Chemistry, University of Bayreuth, 95440 Bayreuth, Germany
Hybrid lead halide perovskites are a promising candidate for the absorbing layer in solar cells due to their excellent optical properties i.e. a direct band gap, a high absorption coefficient throughout the entire visible spectrum and a low exciton binding energy. It is known that the precise stoichiometry of the additives during film preparation is important for the device performance. For example a small amount of typically 10% extra PbI2 was found to be beneficial for the performance. However, the mechanism of how incorporations of additional PbI2 influences the optical and electronic properties and the role of grain boundaries are not completely understood yet. We therefore performed temperature dependent steady-state absorption and photoluminescence spectroscopy to investigate the impact of additional PbI2 and the grain size on the fundamental optical properties in thin films of CH3NH3PbI3.