Leafy light harvest

A research team in Sydney has created molecules that mimic those in plants which harvest light and power life on Earth.

‘A leaf is an amazingly cheap and efficient solar cell,’ said Dr Deanna D’Alessandro, a postdoctoral researcher in the Molecular Electronics Group at the University of Sydney. ‘The best leaves can harvest 30 to 40 percent of the light falling on them. The best solar cells we can build are between 15 and 20 percent efficient, and expensive to make.’

‘We’ve recreated some of the key systems that plants use in photosynthesis,’ said Deanna.

Bacteria and green plants use photosynthesis to convert light energy into usable chemical energy. Wheel-shaped arrays of molecules called porphyrins collect light and transfer it to the hub where chemical reactions use the light energy to convert carbon dioxide into energy-rich sugar and oxygen.

‘This process, which occurs in about 40 trillionths of a second is fundamental to photosynthesis and is at the base of the food chain for almost all life on Earth,’ said Deanna.