Dresden 2017 – wissenschaftliches Programm
CPP 3.3: Vortrag
Montag, 20. März 2017, 11:00–11:15, ZEU 222
Analysis of electronic trap states in methylammonium lead halide perovskite solar cells via thermally stimulated current — •Philipp Rieder1, David Kiermasch1, Mathias Fischer1, Kristofer Tvingstedt1, Andreas Baumann1,2, and Vladimir Dyakonov1,2 — 1Experimental Physics VI, Julius Maximilian University of Würzburg, 97074 Würzburg — 2Bavarian Center for Applied Energy Research ZAE, 97074 Würzburg
While power conversion efficiencies already exceeding 22% have been achieved for organo lead halide perovskite solar cells, a complete understanding of its fundamental working principles is still missing, but nonetheless essential to further improve this type of thin film photovoltaic. To address the impact of electronic trap states on device performance, we probed solution processed methylammonium lead halide perovskite solar cells via thermally stimulated current (TSC) analysis. Thereby, after cooling the sample down to 10 K, possible trap states are filled optically and gradually released again by heating the sample back up to 300 K. This causes a weak current to flow, which allows to draw conclusions about the trap state density as well its energetic depth. We probed perovskite solar cells in normal as well as inverted device configuration to identify the influence of different transport layers on the energetic trap landscape and observe a substantial addition in the case of the commonly used TiO2. Additionally, we studied the effect of incorporating bromine as well as chlorine to partly replace the iodine on the electrically active trap state distribution of the photoactive semiconductor.