Prof. Dr. Maria Wächtler

RPTU Kaiserslautern-Landau

Fachbereich Chemie und Landesforschungszentrum OPTIMAS

Insights into semiconductor nanocrystal based photocatalysis– connecting charge carrier dynamics and activity

Dr. Quinten A. Akkerman

Chair for Photonics and Optoelectronics, Nano-Institute Munich, Department of Physics, Ludwig-Maximilians-Universität (LMU), Königinstraße 10, 80539 Munich, Germany

Perovskite Quantum Dots: From synthesis to their excitonic properties

Colloidal lead halide perovskites (LHP) nanocrystals (NCs) are popular light-emissive materials for optoelectronic devices, of interest for LEDs, LCDs, lasers and quantum light sources. Most studies on LHP NCs focus on relatively large NCs exceeding 10 nm in size, exhibiting weak to no quantum confinement effects. Recently, we showed that perovskite quantum dots (QDs) can be synthesized using a newly developed synthesis route, resulting in perovskite QDs that are tunable between 3 and 13 nm range. These QDs have a wide range of compositions (CsPbBr₃, CsPbCl₃, CsPb(Cl:Br)₃, CsPbCl₃:Mn²⁺, FAPbBr₃ and MAPbBr₃) and exhibited multiple well-resolved excitonic transitions.In this talk I will give an overview of how we synthesis such QDs,^[1-3] how we can tune their surface chemistry,^[4,5] and the quantum  properties these materials exhibit.^[6,7] Using in-situ spectroscopy, we can also learn what drives the synthesis of such nano-systems, and gain a mechanistic insight into their surface and defect chemistry.^[1,4] By combining these QDs with closely bound dye molecules, we can make hybrid QD-dye systems that exhibit efficient energy transfer (ET) from QDs to dyes, even with minimal spectral overlap.^[5] Finally, I will discuss how we use ultra-fast transient spectroscopy to look at the excited state dynamics of these QDs, and how we can understand their optical gain and amplified spontaneous emission.^[6,7]

Clemens Küpper, Max Planck Institute for Biological Intelligence

Alternative Reproductive Tactics as Drivers of Intraspecific Diversity

Hybrid Information

Webinar link: https://mpi-biochemistry.zoom-x.de/s/64180753743
Password: 192953
Webinar ID: 641 807 537 43