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 1.3: Hauptvortrag
Dienstag, 2. April 2019, 10:15–10:45, H32
Defect activity in lead halide perovskite semiconductors — •Silvia Motti — Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, OX1 3PU, Oxford, United Kingdom
Perovskite semiconductors have recently emerged as promising materials for optoelectronic applications, with photovoltaic efficiencies that have now reached over 23%. Great research effort has been employed towards understanding how the perovskite crystalline and electronic structure relates to their remarkable defect tolerance and surprisingly long carrier lifetimes and high open circuit voltages. At the same time, the material instability often interferes with experimental observations, besides posing a major challenge for commercial application. A comprehensive investigation of defect activity in lead halide semiconductors was conducted by combining computational studies with experimental evidences from optical spectroscopy. It was possible to identify the most predominant charge-trapping point defects in MAPbBr3 and MAPbI3 and their role in recombination dynamics, explaining the defect tolerance in these semiconductors. Moreover, the reactivity of such defects under external stimuli could be associated with the photoinstabilities observed in these materials, allowing for the development of successful strategies to control them. This understanding opens the possibility of developing intelligent fabrication methods and further optimizing performance and stability of perovskite optoelectronic devices.