If inorganic semiconductors are currently top of the heap in pholtovoltaic technology, organic molecules with identical properties are starting to appear, which could knock the inorganic semiconductors off of the top of that green energy production heap.

In the race to provide green energy, the attraction of photovoltaic solar cells is easy to understand. In this context, the team of the Molecular Engineering Laboratory of Angers, along with their colleagues at the Laboratory of materials, surfaces and processes for catalysis at Louis Pasteur University in Strasbourg in France, have just achieved a record output of 1.7 % ! This record may be surprising. Rooftop photovoltaic cells usually produce an output of around 15%. Why therefore should a shout of yippee go out for only 1.7% output? Simply because the breakthrough accomplished in France concerns organic cells.

There will need to be more experimentation in the future but even in this case, outputs obtained in laboratories brush close to 5%. Jean Roncali of the Angers team explains that contrary to crystalline silicon, which is inorganic, and production of which requires very high temperatures, the manufacture of the organic cells involves low financial costs and energy cost, and also a low environmental impact.

These are not negligible arguments when talking about renewable energy sources. Speaking of output in the order of around 5 %, Mr Roncali explianed that what makes this a new achievement is that this is done without polymers. For a decade, most of the research on organic cells has been based on the use of polymers, which pose a number of problems: synthesis, purification, control of structure and molecular mass.

To work around these obstacles, the French researchers preferred to work on other types of “combined” molecules. Their first prototypes were presented in 2005, with an output of about 0.2 %. It is this output which has been pushed today to 1.7 %. Ultimately, these figures may seem low, but one should not lose sight of the fact that their use will be on surfaces much larger than current photovoltaic panels. Why not imagine, for example, covering a whole building with a paint boosted with this new type of molecule? Low performance would then be largely compensated by the available surface.

From an article by Laure-Rivory. cc 2.5 Please link to this page.