Technology Transfer
The center of our experimental activities is usually a home-built confocal laser-scanning microscope on an optical table where we combine it with spectroscipic components. The main technique is fluorescence spectroscopy but also Ramn- or reflection spectroscopy is possible. Using commercial microscopy objectives the light of several different laser sources mainly in the visible spectral range but also in the near infrared is focussed onto an diffraction-limited spot of a few hundred nanometer in order to achieve a respective spatial resolution. Thoses objectives with high numerical aperture allow for the highly effective collection of the light emitted or back scattered from the sample. On the one hand, the open setup on an optical table enables a versatile analysis of the light: this could be a spectral analysis with high spectral resolution using low-noise CCD detectors or the measurement of fluorescence decay curves using pulsed laser and time-correlated single photon counting. In the latter context our streak camera system allows for a particular high time resoluationdown to 2ps in addition to the possibility to measure the fluorescence signal with simultaneous spectral- an time-resolution. On the other hand, the spectroscopic methods can be combined with other measurement techniques or can even be conducted simultaneously. These additional techniques can be atomic force microscopy - for the measurement of the topography (AFM), the spatial charge distribution (EFM) or the contact potential difference (KPFM) – but also photocurrrent or photovoltage measurements. If these measurements are carried out in a suitable reactor also electrochemical meausrements can be conducted simultaneously.
On the one hand, the correlation of maps of different sample properties with high spatial resolution allows for new insights into the chemical or physical processes in the sample. On the other hand the customized combination of different measurement components might lead to new experimental methods. With the help of our experimental equipment and our know how we can support these kind of projects.
Contact:
Prof. Dr. Alf Mews
Tel.: +49 40 42838-3431
Fax: +49 40 4273-14796
E-Mail: [email protected]