New material resembling paper, entirely made of wood fibers, holds huge promises for the future of solar cells. Developed by scientists from the University of Maryland, the South China University of Technology, and the University of Nebraska-Lincoln, it handles the problem that every other material used in solar cells has- that of having to sacrifice optical haze for optical transparency and vice versa.
Efficiency of solar cells is determined by the properties of the materials that make them up. Ideally, these should provide maximum light transmission through optical transparency, as well as maximum scattering, which boosts absorption of light. Unfortunately, until now, scientists have not been able to develop the ideal material that has a good percentage of both properties, and therefore the performance of the existing solar cells has always been just that little bit behind optimal.
However, this is likely to change soon. A study that appeared in one of the latest issues of Nano Letters, presents a revolutionary new material that has 96% transparency and 60% haze, as opposed to the existing materials with 90% of the former, and less than 20% of the latter. The material is much cheaper and much more environmentally friendly than its plastic ancestors, as it is made entirely of wood fibers.
Of course, the most obvious question that anyone would ask is how did the researchers overcome the problem with low transparency associated with conventional paper? The answer is in the nanoporous structure, which is different from the microporous one found in regular paper. The team eliminated the microcavities in the typical paper by treating wood fibers in order to remove the hydrogen bonds between the microfibers within them. The result is a very tightly packed structure containing nanopores, formed after the collapse of the wood fibers.
In order to test the suitability of the new material to be used in solar cells, the team applied the wood-fiber paper onto a silicon slab surface. After exposing it to sunlight, the researchers observed 10% boost in efficiency. The tests also indicated that there is no need of complete replacement of already existing solar panels in order to take advantage of the new technology. All that is required is to apply an extra coating onto the already existing cells.
The team is very enthusiastic about making the product commercial and considering the incredible benefits it might bring to the solar industry, their goal might actually be very close to being achieved.
Image (c) ACS