Distributed computing: the Clean Energy Project
World Community Grid and the Clean Energy Project are assembling a virtual laboratory to build thousands of organic compounds in order to discover those that are the best candidates for future solar cell research. With the aid of World Community Grid, new molecular materials with specific properties will be designed in software, instead of having to actually synthesize and test the molecules in an actual chemical experiment. Thus rather than measuring the response of the molecules to sunlight, scientists from the Aspuru-Guzik group at Harvard University will be able to look at their calculated molecular properties and estimate their performance as solar cells. To be successful, they will need to achieve the highest levels of accuracy available with current computational chemistry methods - and must do so for tens of thousands of molecules.

IMEC reports method to extend lifetime of organic solar cells
The efficiency and operation of organic solar cells strongly depends on the nanomorphology of the active layer, i.e. on a stable mix of organic compounds that can trap the light’s energy and transport it to an electric contact. IMEC already reported such cells based on P3HT:PCBM with efficiencies near 5%. But to date, the lifetime of these cells is far too short for commercial applications, for which 5 years is seen as a minimum. (...) [IMEC has now] introduced a new method and new conjugated polymers to stabilize the nanomorphology of the active layer making it far more robust to phase segregation under prolonged operation. Experiments on bulk heterojunction organic solar cells based on this new material showed no degradation of the efficiency after more than 100 hours whereas reference cells degraded already after a few hours. This means that a lifetime improvement of at least a factor 10 can be obtained.

Printing Highly Efficient Organic Solar Cells
[Nanomaterials, N. Hoth, Konarka] The technological attraction in organic solar cells is their compatibility to printing processes. However, up to today, nearly no literature on “printed” organic solar cells have been published and the major body of the research work was done by spin coating or blading techniques. Transferring the spin-coating or doctor blading process currently used for the fabrication of bulk heterojunction solar cell to a printing process holds morphological challenges that have not been observed or reported up to today. We highlight these challenges and we show that inkjet printing of organic bulk heterojunction solar cells requires completely novel approaches and skill sets compared to the current state of the art (...) report a new record power conversion efficiency of 3.5% for inkjet printed poly(3-hexylthiophene):fullerene based solar cells.