You can deposit thin films of silicon on to, say, ordinary glass. Usually, this is done with CVD, although I think epitaxial growth is also a popular technique.

You can deposit thin films of silicon on to, say, ordinary glass. Usually, this is done with CVD, although I think epitaxial growth is also a popular technique. The problem is that this tends to produce amorphous silicon, which is not especially efficient. There is a good deal of work to get to the point where monocrystalline silicon thin film cells are viable outside of the lab, though.