Solar power from water-based ‘artificial leaves’
“Natural” solar cells have the potential to be less expensive and more environmentally friendly than current silicon-based solar cells…Posted Oct 20, 2010
A team of US and Korean scientists have invented water-based ‘artificial leaves’ that can act like solar cells to produce electricity.
The flexible devices have the potential to be less expensive and more environmentally friendly than standard silicon-based solar cells, said the researchers.
The artificial leaves are made of a water-based gel infused with light-sensitive molecules coupled with carbon-coated electrodes.
Mimicking nature, the artificial leaves work in a similar way to plants’ leaves, with sun’s rays exciting the light-sensitive molecules to produce electricity, or in the case of a plant, sugar.
In one experiment, the researchers actually infused the gel with plant chlorophyll, the green pigment in leaves that converts the energy from sunlight into sugars, said the study’s lead author, Dr. Orlin Velev of North Carolina State University, in a press release.
In order to draw in solar energy the way nature does, natural products like chlorophyll can be used in the artificial leaves to replace synthetic light-sensitive molecules to create the same reaction. The water-gel matrix in these new leaves allows for both natural products like chlorophyll and synthetic light-sensitive molecules to be used interchangeably.
“The next step is to mimic the self-regenerating mechanism found in plants,” Velev said. “The other challenge is to change the water-based gel and light-sensitive molecules to improve the efficiency of the solar cells.”
In the future, soft sheets of artificial-leaf solar cells could blanket roofs to generate electricity, said Velev.
“We do not want to overpromise at this stage, as the devices are still of relatively low efficiency and there is a long way to go before this can become a practical technology,” Velev continued.
“However, we believe that the concept of biologically inspired ‘soft’ devices for generating electricity may in the future provide an alternative for the present-day solid-state technologies.”
The research was published in the Journal of Materials Chemistry on Sept.21.
Hyung-Jun Koo and Dr. Orlin D. Velev, “Aqueous soft matter based photovoltaic devices” Published: Sept. 21, 2010, in Journal of Materials Chemistry