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 1.5: Hauptvortrag
Dienstag, 2. April 2019, 11:15–11:45, H32
Unravelling the origin of double peak emission of hybrid perovskites — •Fabian Panzer — Department of Experimental Physics II, University of Bayreuth, Bayreuth, Germany
The optical properties of hybrid perovskites are known to be sensitively interconnected with their structure, which is soft and thus prone for changes. Double photoluminescence (PL) peaks have been reported at low temperatures, and recently also at room temperature, though there is still no consensus about the origin of this double PL peak structure. Here we show that the occurrence of the additional PL peak is not limited to one specific material composition and that it occurs in single crystals as well as in thin films, rendering it a general phenomenon. We systematically investigate the origin of this additional PL feature by measuring and analyzing temperature-dependent one- and two-photon-induced photoluminescence. Together with fluence dependent measurements, optical modelling and systematic surface treatments, we can differentiate the impact of various possible physical and optical effects such as photon recycling, self-absorption, excited state diffusion and surface states, in order to gain a detailed and elaborated understanding on the occurrence of multiple PL peak phenomena in hybrid perovskites.