Organic solar cells that can convert ambient light into electricity have been developed by a research group consisting of Swedish and Chinese scientists.
These cells use the light from the environment (much weaker than the light that a solar cell can get if it is placed outside, of course) to produce low levels of electricity, levels that are still considered sufficient to feed millions of small devices and the ‘Internet of Things’ will come online in the coming years.
These are usually devices that act as sensors and inevitably have to work with batteries. The latter will need to be recharged or modified, which is tricky and expensive. These organic solar cells are flexible, economical to build and can adapt to different aspects of light, but they can be applied everywhere because they are very small at the expansion level.
Researchers have developed new materials that they have used as an active layer in organic cells, allowing them to absorb ambient light. Initial tests showed that a solar cell of one square centimeter, exposed to ambient light with an intensity of 1000 lux, can convert 26.1% of that energy into electricity.
A second solar cell, a little larger, of 4 cm in the square, still manages to maintain energy efficiency of 23%. According to Feng Gao, a researcher at Linköping University, this is a “great promise” in the context of feeding devices for the Internet of Things.