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HL: Fachverband Halbleiterphysik
HL 13: Poster Session I
HL 13.12: Poster
Montag, 12. März 2018, 17:30–19:30, Poster B
ultrafast Auger-mediated hole trapping and coherent phonon dynamics in CdSe/CdS core/shell colloidal semiconductor nanoplatelets — •shuo dong1,2, jie lian3, yinthai chan3,4, and zhiheng loh1 — 1Division of Chemistry and Biological Chemistry, and Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore — 2Fritz Haber Institut of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany — 3Institute of Materials Research & Engineering A*STAR, 3 Research Link, Singapore 117602, Singapore — 4Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
The narrow absorption and photoluminescence emission spectra of atomically flat, quasi-two-dimensional, colloidal semiconductor nanoplatelets (NPLs), which originate from the atomically precise thickness, have motivated increasing research interest. Here, we report the use of ultrafast transient absorption spectroscopy to study the early-time carrier dynamics of CdSe/CdS core/shell NPLs. By selective monitoring the excitonic transitions, fluence-dependent measurements reveal a sub-picosecond Auger-mediated hole trapping process. The low-frequency oscillatory features observed in the first-moment time traces can be assigned to the hitherto undetected coherent acoustic phonons (5 and 20 cm-1). The elementary carrier and phonon dynamics of colloidal semiconductor NPLs observed herein could potentially influence their optoelectronic properties.