Today's solar cell multi-GW market is dominated by crystalline silicon (c-Si) wafer technology, however new cell concepts are entering the market. One very promising solar cell design to answer these needs is the silicon hetero-junction solar cell, of which the emitter and back surface field are basically produced by a low temperature growth of ultra-thin layers of amorphous silicon. In this design, amorphous silicon (a-Si: H) constitutes both "emitter" and "base-contact/back surface field" on both sides of a thin crystalline silicon wafer-base (c-Si) where the electrons and holes are...