Extremely Narrow Band Gap,∼1·50Ev, Amorphous Silicon

Abstract

ABSTRACTHydrogenated amorphous silicon (a-Si:H) films were prepared by a layer-by-layer (LBL) argon treatment technique. Thin amorphous silicon layers are first deposited and then treated by Ar. Thick films are built up by repeatedly the process many times. By reducing the deposition rate during deposition time (T, sec), a-Si:H with the gaps narrower than 1·55eV were prepared at substrate temperature lower than 300°C. These narrow-gap films contained less than 2 at.% hydrogen and had rigid Si network. Also, these narrow gap films exhibited good light soaking stability.