Self-Assembling Solar Cells
What can a scientist do with salad dressing apart from telling you that it increases the taste of salad manifold? But that’s the beauty of this profession. As Newton could give some theories when he saw an apple falling from a tree, salad dressing can inspire scientists towards a brand new type of solar cells. The researchers managed to create a cheap, efficient and very simple method of making solar cells. The USP of these solar cells is that they self-assemble on a variety of substrates. The new technique draws parallel from the fact that oil and water don’t mix at all. Another unique fact is forces the elements of electronic components for example solar cells assemble themselves at the boundaries between the two types of liquids. This work was recently published in Proceedings of the National Academy of Sciences (PNAS).
University of Minnesota researchers used a number of other methods to create solar cells. It is believed that the technology can be used on commercial scale too. This method has one more benefit that it can force components to self-assemble onto a range of substrates, and not just a select, expensive few.
Till now scientists are applying the use of gravity on such mechanisms. Many lines are engraved on a substrate that was put inside a liquid. Now various electronic components settle down at designed locations. But such methods have their own limitations. They face problems like low yields, and low concentration. Therefore commercial application of such a mechanism was almost impossible. UM expert Heiko Jacobs, the leader of the research team, expresses his opinion, “That’s what we tried for at least two years and we were never able to assemble these components with high yield – gravity wasn’t working.”
He explained his innovative approach further, “Then we thought if we could concentrate them into a two-dimensional sheet and then have some kind of conveyor belt-like system we could assemble them with high yields and high speed.”
The researchers constructed a system at the boundary between water and oil. The substrate is dipped into the liquid, and then gently pulled out. Small components settle down into place, and the method is enormously effectual. The research team was successful to fit about 64,000 elements on a substrate in less than three minutes.
University of Washington in Seattle Nanoengineering Professor Babak Parviz explains, this work is a “clear demonstration that self-assembly is applicable across size scales. Self-assembly is probably the best method for integrating high-performance materials onto unconventional substrates.” Currently the UM team is trying to find out the minimum and maximum sizes that can be produced for electronic components. In short, we can say that the technology could transform the solar cell industry in that it allows for the large-scale assembly of high-quality electronic components.
The technology can be utilized for the highly efficient solar cells that can be built quickly and cheaply on various materials.