Ultrafast Dynamics Group
Frédéric Laquai's Group


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.


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.