On June 1st we were very happy to welcome Dr. Andrew Strikwerda to the THz group. In the coming years he will be involved in our high-power THz research. Drew is funded by a postdoctoral fellowship from the prestigious H. C. Ørsted foundation and by the Danish Council for Independent Research|Technology and Production Sciences, via the HI-TERA project.

Drew recently obtained the Ph.D. Degree from Boston University, where he worked in the group of Prof. Rick Averitt.

 

The European Optical Society held the 3rd Topical Meeting on Terahertz Science and Technology in Prague on June 17-20, 2012. The THz group was present at the meeting with two student presentations by Jonas Buron and Maksim Zalkovskij, speaking about their work on graphene and metamaterials, respectively. Former member of the group, Dr. David Cooke (now at McGill University, Montreal, Canada), delivered an invited talk on his work on polymer solar cells which was performed in the group.

Group leader Prof. Peter Uhd Jepsen, was chairman of the conference together with Prof. Petr Kuzel, Chech Academy of Sciences.

 

April 1st marked the start of Ph.D. student Pernille Klarskov in the THz group! Pernille will be working on the HI-TERA project, funded by the The Danish Council for Independent Research | Technology and Production Sciences (FTP).

 

We have recently invested in a rapid THz scanner system (Picometrix T-Ray 4000) for fast, nondestructive testing of materials. With this system we can now perform 2D and 3D reconstruction of the outer and inner structure of a wide range of materials.

The image below shows the result of THz tomography of a toy horse, revealing the inner structure of the horse. Most prominent are air voids in the central part of the body.

3D THz tomographic imaging of plastic horse  

For more information on the application of THz imaging in your own setting (such as industry, art and cultural heritage conservation), please contact us for further details.

 

Polymer photovoltaics is currently the only technology which can solve major problems with manufacturing cost and speed facing all other photovoltaic technologies. In spite of many advantages, however, the efficiency of polymer solar cells is still rather low compared to silicon-based solar cells.

In a recent paper published in Physical Review Letters, we investigate one of the crucial mechanisms which limit the efficiency of polymer solar cells. We use a unique optical technique, known as ultrafast time-resolved THz spectroscopy, which directly monitors the electric conductivity of the electrical charges generated by light in the solar cell with unprecedented time resolution. Our measurements reveal that within the polymer solar cell, only one third of the electric charges generated by the incoming light are available for current generation in the solar cell device, while the remaining two thirds of the charges are trapped. A modification of this ratio will directly influence the overall efficiency of the solar cell. This gives solar cell developers an invaluable experimental tool in the quest to increase the efficiency of next generation solar cells by new polymer chemistry and device design.

The investigation was spearheaded by Dr. David Cooke, who is now heading the Ultrafast THz Laboratory at McGill University, Montreal, Canada, in close collaboration with world-leading polymer solar cell expert, Prof. Frederik Krebs, Department of Energy Conversion and Storage at the Technical university of Denmark.

Read the official DTU press release (in Danish).

Citation:
D. G. Cooke, F. C. Krebs, and P. U. Jepsen, “Direct Observation of Sub-100 fs Mobile Charge Generation in a Polymer-Fullerene Film,” Phys. Rev. Lett. 108, 056603 (2012)

 

From March 1st 2012 Morten Møller will join the THz group as a new master student. Welcome!

© 2012 Terahertz.dk Our research is carried out at DTU Fotonik - Department of Photonics Engineering, Technical University of Denmark. Suffusion theme by Sayontan Sinha