Amorphous silicon MIS solar cells

AMORPHOUS silicon grown by the rf glow discharge decomposition of silane in the process developed by Spear and Le Comber^1,2 is one of the most promising materials found so far in the search for a cheap, large-area solar cell. Only two results, albeit encouraging, have been reported by RCA for p-n cells³ (AMI efficiency 2.4%) and anti-reflection coated platinum Schottky barrier cells⁴ (AMI efficiency 5.5%), but with area only =2×10^-2 cm². We report here the achievement of comparable efficiencies for a Schottky barrier cell, incorporating an insulating layer between the metal and semiconductor (an M-I-S cell) and with significantly greater area. The insulating layer is tailored to compensate for the low work function of the cheaper barrier metal (nickel) which we have used^5-9, leading to higher cell voltages otherwise obtainable only with higher work function metals. This is a significant step forward in the development of large area terrestrial solar cells. © 1978 Nature Publishing Group.