Friday, 27 February 2009
Do you remember your biology lessons? All about photosynthesis? We used to do an experiment that involved taping a piece of foil on to a plant's green leaf. After a time we tested the leaf for starch, and lo and behold, the leaf that had been hidden from the sun had no starch. And that was supposed to prove that green leaves needed the sun to produce starch using the magical process of photosynthesis.
Although that seems something of a leap of faith now (how? why? couldn't foil have some mystical de-starching properties?), at the age of 12 it seemed a satisfactory demonstration and amazing that plants could change sunlight into starch. Green plants can do this, trap the power of the sun and convert it into food. It is the original green energy, a source of solar power, though we didn't think to call it that then.
How great it would be if we could use green plants as sources of solar power, or if we could trap energy in the same way that they do. It isn't so very far fetched as it might seem. Scientists have used nano-technology to create devices that mimic the functions of the molecules involved in the photosynthesis cycle. They have made a photovoltaic device that can absorb light and efficiently convert it to electric current.
"These are early days but the possibilities for the application of this technology for environmentally-friendly energy production are very exciting."
You can read the research paper in Physical Review Letters. I don't think I'll attempt it myself because I can't even understand the title: Photocurrent Enhancement in Hybrid Nanocrystal Quantum-Dot p-i-n Photovoltaic Devices.