Light soaking of hydrogenated amorphous silicon: a short review

Hydrogenated amorphous silicon (a-Si:H) has a long history in the development of photovoltaics, especially in the research field of a-Si:H thin-film solar cells and crystalline/amorphous silicon heterojunction solar cells. More than 40 years ago, Staebler and Wronski reported conductance decrease of a-Si:H induced by light soaking. This phenomenon has been widely investigated for electronic applications. In contrast to that, we found light soaking can also improve dark conductance of a-Si:H when boron or phosphorus atoms are doped into the amorphous network. Here we survey these two photoelectronic effects, and discuss their implementations to silicon solar cells.