Ultrafast Dynamics Group
Frédéric Laquai's Group

Facilities

Electroluminescence spectroscopy (ELS) measures the luminescence emission from a device following charge injection and recombination, for instance, the emission caused by bimolecular recombination of charges in organic solar cells.
Micro-PL refers to spatially-resolved photoluminescence (PL) experiments with a spatial resolution around or better than 1 micrometer.
TA is a differential pulse technique. A short pulse of white light is transmitted through a photoexcited sample and the transmission of the white light is compared to that of a white light pulse transmitted through a non-excited sample. ​​​​​​​​​​
We use two techniques of terahertz spectroscopy in order to probe ultrafast photo-initiated dynamics in active materials used in solar cells.

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Using PIA, the dynamics of excited states in dyes, polymers and organic devices can be observed, and therefore basic processes like charge separation and recombination can be investigated.​​​​
Time resolved photoluminescence spectroscopy probes those excited states that have a radiative decay channel.​​​​​
PDS is a non-destructive and highly-sensitive technique that measures the absorbance of semiconducting materials. 
TDCF is an optical-pump electronic-probe technique, particularly relevant to study the fiel dependance of charge generation, charge exctraction, photogenerated charge density, and charge recombination dynamics in solar cells.