Researchers at Northwestern University in Chicago have found a new way to create solar cells that are obtained as a result of low-cost and have a good performance. Equally important, the solar cells based on the new technology, not tied to the use of toxic or scarce materials, have a longer service life and can be made even more mass than traditional panels.
It has already developed a project of solar cells, which would provide all these benefits. The so-called Gratzel cell, solar cell using sensitizing dyes, was environmentally friendly and cheap to manufacture. The main problem was the technology that created the electrolyte dye-sensitized with an organic liquid which after a certain time to provoke corrosion cell. In such conditions, the battery life was limited to 18 months.
A team from Northwestern University intends to solve the problem of cell Gratzel cell. Nanotechnologist Robert PH Chang and chemist Mercouri Kanatzis put all their knowledge and experience to develop new technology. The first part of the developed solutions — is a semiconductor thin film based on a compound of cesium, iodine and tin called CsSnI3. In the early stages of synthesis of the compound behaves as a liquid, but after — changes physical state, becoming completely solid. As a result, we obtain a fully stable cell based solid.
The second secret of the new development — is nanotechnology. "Our low-cost solar cells using nanotechnology in order to remain stable, providing high efficiency," Chang said. "Due to the presence of millions of cell titanium dioxide nanoparticles, we have a large surface area for absorption. Then we cover every bit of light-absorbing dye »
Scientists describe the composition of its solar cells as follows. One solar cell has a size of 0.5 cm / 0.5 sm/10 microns. After the dye-coated nanoparticles are placed as in the form of a cell, where the material is poured CsSnI3, yet in a state of liquid. Liquid polymer evenly coats the nanoparticles and then hardens. Under the action CsSnI3 dye, which performs the function of the cell absorption of sunlight begins to evaporate, eventually find themselves prisoners between the two semiconductors — an array of nanoparticles and CsSnI3.
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Solar cells created using this technology could be effective the approximately 10.2 percent — a record for that of the solar panels. In previous cell Gratzel cell efficiency level was roughly between 11 and 12 percent. But despite the fact that the effectiveness of the new technology a little less, the practice shows that 10 per cent — this is a value large enough to commercialize the technology.
Chang said that the concept is applicable to various types of solar cells, and the technology to create thin-film solar compatible with automated production. The next step is to create a team and test full-sized solar panels on the basis of the developed structures.