Indoor organic solar cells

Indoor-solar cells

New developments form Swedish and Chinese scientists have led to a development of a new kind of organic solar cell that has been optimised to convert ambient indoor light into electricity.

Producing only a low power, it should well be enough to power the many products that the internet of things will bring into everyone’s world.

With the growth of the internet of thing (IOT) both in homes and in public spaces this technology is a step in the right direction away from the land of cables and reliance on coal fueled wall plus into the realms of free energy.

Source: Thor Balkhed

No longer will there be such a need to continually replace batteries – both an expensive exercise and harmful to the environment. As many of these IOT devices will essentially not require masses of power to drive functionality, these solar cells will cater to the needs of cheap and renewable energy.

This is where organic solar cells come in.

These indoors solar cells are flexible, cheap to manufacture and suitable to manufacture as large surfaces in a printing press. A significant further advantage: the light-absorbing layer consists of a mixture of donor and acceptor materials, which gives considerable flexibility in tuning the solar cells such that they are optimised for different spectra—for light of different wavelengths.

Researchers in Beijing and Linköping, Led by Jianhui Hou and Feng Gao based in Beijing, have developed a new combination of acceptor and donor materials, with a carefully determined composition, to be used as the active layer in an organic solar cell. The combination absorbs exactly the wavelengths of light that surround us in our living rooms, at the library and in the supermarket.

Currently there are two variants of an organic solar cell. One variant has an area of 1cm2 and the other 4cm2. The smaller solar cell was exposed to ambient light at an intensity of 1000 lux, and the researchers observed that as much as 26.1% of the energy of the light was converted to electricity. The organic solar cell delivered a high voltage of above 1 V for more than 1,000 hours in ambient light that varied between 200 and 1000 lux. The larger solar cell still maintained an energy efficiency of 23%.

“This work indicates great promise for organic solar cells to be widely used in our daily life for powering the internet of things,”

Feng Gao

Jianhui Hou, professor at the Institute of Chemistry, Chinese Academy of Sciences, added:

“We are confident that the efficiency of organic solar cells will be further improved for ambient light applications in coming years, because there is still a large room for optimization of the materials used in this work.”

Jianhui Hou

The Biomolecular and Organic Electronics research group at Linköping University, under the leadership of Olle Inganäs has been for many years a world-leader in the field of organic solar cells.

Olle Inganäs and his colleague Jonas Bergqvist, founded, and are now co-owners of a company, which focuses on commercialisation of solar cells for indoor use.

Hopefully soon we will see the real world impact of this wonderful new technology for a cleaner more renewable future of power in our every day lives.