A team of researchers at MIT have come up with a way to increase the efficiency of thin-film crystalline silicon solar cells by as much as 50%. What they’ve done is to combine an antireflection coating on the front of the cell along with a multi-layered reflective coating and a tightly spaced diffraction grating to the back of the cell. The net effect is to trap light in the cell longer – this gives the cell a better chance to take that light and convert it into electricity. Lab tests have shown that cells built this way could take the 10% efficiency seen by most thin film silicon cells and increase that up to 15.6%.
Unfortunately at this time the process used to make these cells is “not production ready.” The process used to create the diffraction grating is called holographic lithography, and is only performed at a few specialized locations, and the reflective coatings used wouldn’t be economical in mass production. However, as the technology improves, the cost could come down significantly.
via: Greentech Media