In the 1980s, advances in the passivation of both cell surfaces led to the
first crystalline silicon solar cells with conversion efficiencies above 20
%. With today's industry trend towards thinner wafers and higher cell effic
iency, the passivation of the front and rear surfaces is now also becoming
vitally important for commercial silicon cells. This paper presents a revie
w of the surface passivation methods used since the 1970s, both on laborato
ry-type as well as industrial cells. Given the trend towards lower-cost (bu
t also lower-quality) Si materials such as block-cast multicrystalline Si,
ribbon Si or thin-film polycrystalline Si, the most promising surface passi
vation methods identified to date are the fabrication of a p-n junction and
the subsequent passivation of the resulting silicon surface with plasma si
licon nitride as this material, besides reducing surface recombination and
reflection losses, additionally provides a very efficient passivation of bu
lk defects. Copyright (C) 2000 John Wiley & Sons, Ltd.