Thin film solar cells are much more flexible than the more common crystalline silicon solar cells. Silicon solar cells are what are known as “1st generation” solar cells. The “2nd generation” of thin film solar cells evolved as scientists tried to overcome some of the limitations of the 1st generation such as high manufacturing costs and materials.
Thin films use much less material and can be constructed into the solar cell framework much more easily than the 1st generation cells. This makes them more light-weight and cheaper. They are also less rigid so they can be put onto flexible materials to make them bendy. Thin films have been made out of lots of different varieties of semiconducting materials, including amorphous silicon (a-Si) as opposed to crystalline silicon (c-Si) used in 1st generation cells; copper indium gallium diselenide (CIGS) and cadmium telluride (CdTe).
How do they work?
They work in a generally similar manner to the first generation crystalline silicon cells. However materials are used that absorb light more strongly than silicon enabling thinner films to be used.
What are the limitations?
Unfortunately, although they are cheaper, they are also less efficient than the 1st generation of solar cells. The best efficiencies have reached 18%. The materials used are often toxic or rare elements in great demand for use in other applications like flat screen displays. Cadmium, for example, is banned in many applications in Europe except for use in solar power, but if the ban expands, then these solar cells could no longer be used.
Perovskite Solar Cells
A new brand of solar cells that have arisen in the past few years are based upon materials known as perovskites. Learn more about this exciting new solar cell type.