Dresden 2017 – wissenschaftliches Programm
CPP 3.7: Vortrag
Montag, 20. März 2017, 12:15–12:30, ZEU 222
Impact of bromine doping on recombination kinetics in perovskite solar cells — •David Kiermasch1, Phillip Rieder1, Kristofer Tvingstedt1, Andreas Baumann2, and Vladimir Dyakonov1,2 — 1Experimental Physics VI, Julius Maximilian University of Würzburg, 97074 Würzburg — 2Bavarian Center for Applied Energy Research (ZAE Bayern) Bayern, 97074 Würzburg
Organo metal halide perovskite solar cells exhibit exceptionally good power conversion efficiency values exceeding already 20%. To allow further improvements it is important to understand the limiting processes e.g. charge carrier recombination in this new photovoltaic technology. Most of the recombination studies presented so far have been focused on perovskite films or crystals but only a few have studied the charge carrier dynamics in solar cell devices. We report on charge carrier lifetime values in bromine containing planar perovskite solar cells with varying the bromine content. The lifetime and corresponding charge carrier density has been derived from transient photovoltage (TPV) and charge carrier extraction (CE) experiments. We found increased lifetime values in solar cells with bromine (MAPb(I3−xBrx)3) compared to pure methylammonium lead iodine (MAPbI3). Furthermore, the CE signals from the bromine containing solar cells can be divided in two different extraction parts on different time scales leading to anomalously high extracted charge values. We discuss the experimental findings in regard of possible different contributions to the CE signal.