Solar cells to charge portable devices

BANGALORE, INDIA: An organic solar cell that can recharge a lithium-ion battery of portable electronic devices (like e-book readers, cameras, and mobile phones) has been developed by the scientists at University of Warwick and Molecular Solar.

Even without connecting the multiple individual cells in series, the solar cell generates enough voltage to recharge a lithium-ion battery directly, claim the researchers. "Organic photovoltaic (OPV) cells, the so-called 'third generation' of solar technology, offer exciting opportunities thanks to the potential for very cheap manufacture, lightweight, low profile photovoltaics compatible with flexible substrates, which means they are ideally matched to portable electronic device applications," said the researchers.

For the first time, scientists have demonstrated a cell with an open circuit voltage of over 7V which delivers maximum power at more than the 4.2V needed to power a standard lithium ion battery using ultra high voltage OPV cells.

"We have taken a big step towards cheap-to-make solar chargers which can top up your devices whenever they are being used - both indoors and out," said Professor Tim Jones, one of the lead researchers at University of Warwick, along with Dr. Ross Hatton and Professor Mike Shipman.

"A small light-weight solar charger no bigger than a credit card can be fitted to the battery of an e-book reader for example, and constantly top it up with power while you are reading it, even if you are sitting inside on the sofa. Alternatively, this kind of solar cell could be ideal for outdoor use as it is light-weight and portable. The next step is to extend this technology outside the laboratory to make cheap OPV chargers available on a commercial scale through Molecular Solar," explains Prof Jones.