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Academic Report by the Division of Precision Measurement Physics at APM on Mar 17,2023


LectureCharge Carrier Dynamics in Nanostructures Studied by FemtosecondLaser Spectroscopy

TimeMar 17 2023Wed.) 15:00

Room: M1017

 Speecher: Prof Jinjun Liu University ofLouisville

Brief introduction of the presenterProfessor of Chemistry and Adjunct Professor of Physics atthe University ofLouisville (UofL);Spectroscopy Theme Leader of the Conn Center forRenewable Energy Research at UofL;A postdoc in the research group of Prof Frederic Merkt aETH Zurich (2007-2010):Ph.D.at the Ohio State University (2001-2007),B.S. in Physics at East China Normal University

Abstract of the presentationUltrafast laser spectroscopy is a powerful tool for the investigation of charge and energy transferprocesses in molecules and condensed-phase materials. Our research group uses the femtosecondtransient absorption (TA) technique to study charge carrier dynamics in nanomaterialsIn this talk, I will first introduce the principles ofultrafast TA spectroscopy. Results from two recentproiects will be presented to illustrate the effectiveness and limits of the spectroscopic technique.In the first experiment, femtosecond TA spectroscopy was employed to investigate photoinduceaexciton dynamics in three novel CH3NH3PbBr3 perovskite nanostructures: nanocrystals (0D)nanowires (ID), and nanoplatelets (2D). Time scales of different charge carrier processes weredetermined in the experiment.

In the second experimentexcited-state dynamics of molecule-like ligand-passivated (CdSe)34nanoclusters (d=l.6 nm) was monitored by femtosecond TA spectroscopy. In addition, sub.picosecond hole transfer from a nanocluster to its strongly bound ligand shell was observedUnderstanding charge carrier dynamics in nanostructures and on their interfaces can aid in thedesign ofhigh-efficiency photovoltaic and light-emitting devices.

Inviter: Xin Tong Research prof.