Berlin 2018 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 48: Focus: Fundamental Physics of Perovskites I - organized by Lukas Schmidt-Mende and Vladimir Dyakonov

CPP 48.3: Vortrag

Mittwoch, 14. März 2018, 15:45–16:00, C 130

Impact of Temperature Induced Structural Dynamics on the Optical Properties of Hybrid Perovskites — •Fabian Panzer and Anna Köhler — Experimental Physics II, University of Bayreuth

There is still a need in the field of hybrid perovskites to fundamentally understand how changes in the structure, be it the crystal structure, material composition or surface morphology impact on their electronic structure, i.e. their optical properties. Due to their soft nature, hybrid perovskites are prone to changes in their structure, which, for example, can be induced by changing the temperature of the sample, be it realized by cooling in a cryostat,[1] or by local heating due to laser irradiation.[2] Here we present detailed temperature dependent absorption and photoluminescence characterizations on both, polycrystalline thin films and single crystals of the prototypical perovskite methylammonium lead iodide. From our measurements we distinguish between different crystal structures, phase transitions and investigate the influence of disorder on the electronic structure.[3] Furthermore we identify the existence of additional recombination pathways already in the high temperature tetragonal phase of the material. We show that it is possible to induce this phase also at lowest temperatures by local laser heating. This allows to distinguish between the emission features from distinct crystal phases and defect states, to gain full information about the optical properties of the investigated perovskites.

[1] F.Panzer et al., Adv. Energy Mater, 7, 2017, 1700286; [2] F.Panzer et al., Adv. Optical Mater. 6, 2016, 917; [3] S.Singh, C.Li, F.Panzer et al., J. Phys. Chem. Lett, 7, 2016, 3014