An organic solar cell that generates a sufficiently high voltage to recharge a lithium-ion battery directly has been created by scientists from the University of Warwick, in collaboration with spinoff company Molecular Solar.

The development means portable electronic devices such as e-book readers, cameras and some mobile phones could soon be recharged on the move in low light levels and with partial shading.

Organic photovoltaic (OPV) cells, the “third generation” of solar technology, may allow for very cheap manufacture of lightweight, low-profile photovoltaics compatible with flexible substrates, which means they are ideally matched to portable electronic device applications.

The scientists have demonstrated an OPV cell that delivers maximum power with an open circuit voltage of  7V — more than the 4.2V needed to power a standard lithium ion battery. This is the first time these features have been demonstrated using ultra-high-voltage OPV cells, the scientists say.

“A small lightweight solar charger no bigger than a credit card could constantly top the battery of an e-book reader, for example, while you are reading it,” even indoors, said Prof. Tim Jones, one of the lead researchers.

“The next step is to extend this technology outside the laboratory to make cheap OPV chargers available on a commercial scale through Molecular Solar.”