Organic Solar Cells Reach 15% Efficiency
Researchers from the university of Michigan have tested organic photo-voltaic solar cells that successfully reached 15% efficiency.
They’ve estimated that given 20 more years after their release you should be able to get clean electricity for as cheap as 7 cents a kilowatts, whereas in 2017 the average price was 10.5 cents a kilowatt in the US according to the US Energy Information Administration.
The benefit of organic carbon based cells is that they can be more inexpensively manufactured in the shape of flexible rolls that bend around structures and flow freely within the seams of clothing.
An abstract from 2006 reads: Flexible solar cells for clothing
However, up until now photovoltaic cells have lacked the energy efficiency to compete with industry standards. In order to resolve this researchers designed separate layers of carbon to absorb different frequencies of the light spectrum.
The lower layers absorbs electromagneitc wavelengths starting at 350 nanometeres whereas the upper layer absorbs wavelengths up to 950 nanometres wide.
Either cell alone produces 10-11 percent efficiency but when you stack them and add a layer of anti-reflection coating you get 15%.
In order to prevent damage in the lower cells they added an intermediary layer that still allowed light to pass through.
They’ve also demonstrated a fabrication yield of 95% which is good news for industrialisation. One of the scientists commenting saying that 18% efficiency is likely in the near future.