Berlin 2018 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 18: Perovskite and Hybrid Photovolatics
HL 18.11: Talk
Tuesday, March 13, 2018, 12:15–12:30, EW 203
Exciton dynamics in quantum confined CsPbBr3 nanoplatelets — •Moritz Gramlich, Bernhard J. Bohn, Yu Tong, Lakshminarayana Polavarapu, Alexander S. Urban, and Jochen Feldmann — Chair for Photonics and Optoelectronics, Department of Physics, Ludwig-Maximilians-Universität, Munich, Germany
In contrast to bulk perovskite films, new reports have shown that in perovskite nanocrystals the excitonic absorption onset and photoluminescence (PL) peak exhibit a blue shift due to quantum confinement when their size in at least one dimension approaches the exciton Bohr radius of that material [1]. For decreasing thickness of organic-inorganic perovskite nanoplatelets – separated by centrifugation – increasing exciton binding energies and decreasing PL decay times have been observed [2]. Now a new method has been developed which enables the direct synthesis of quantum-confined inorganic CsPbBr3 nanoplatelets of uniform thickness. Here, transient absorption spectroscopy is applied to such nanoplatelets of different thickness varying from two to seven crystal layers to gain additional insight into confinement effects on fast charge carrier dynamics in these systems. A comparison to the results of organic-inorganic perovskite nanoplatelets is givens to investigate the role of the A-site cation.
[1] J. A. Sichert, et al. Nano letters 2015, 15(10), 6521-6527. [2] V. A. Hintermayr, et al. Advanced Materials 2016, 28(43), 9478-9485.