Regensburg 2019 – wissenschaftliches Programm
AKjDPG 1: PhD Focus Session: Photoluminescence of halide perovskites: What does it tell us and what not? (joint session DS/HL/AKjDPG)
AKjDPG 1.4: Vortrag
Dienstag, 2. April 2019, 10:45–11:00, H32
The impact of lead iodide on the recombination kinetics in metal halide perovskites — •Aboma Merdasa1, Alexandros Kiligaridis2, Carolin Rehermann1, Mojtaba Abdi-Jalebi3, Jonas Stöber2, Boris Louis2, Marina Gerhard2, Samuel D. Stranks3, Eva L. Unger1,2, and Ivan G. Scheblykin2 — 1Young Investigator Group Hybrid Materials Formation and Scaling, Helmholtz-Zentrum Berlin für Materialen und Energie, Berlin, Germany — 2Chemical Physics and NanoLund, Lund University, Lund, Sweden. — 3Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, United Kingdom.
Metal halide perovskites are promising semiconductor materials for photovoltaic devices with solar cell efficiencies soaring over 20%, but understanding the fundamental operational principles are lagging behind. One example is the role and influence of lead iodide (PbI2) reportedly being both beneficial and detrimental for a device. Herein, we present a study on the impact of lead iodide on the charge-carrier recombination kinetics in methylammonium lead triiodide (MAPbI3) thin films. We simultaneously acquire spectrally-resolved photoluminescence quantum yield and time-resolved photoluminescence lifetime at excitation wavelengths ranging from 450 nm to 780 nm during hours of light-soaking, and identify a unique radiative recombination mechanism occurring at the PbI2/MAPbI3 interface when charge carriers are generated in PbI2. We thereby provide important insight into the long-debated question of whether excess PbI2 is beneficial or detrimental for charge carrier dynamics in perovskite solar absorber materials.