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91. Recently, there have been some imaginative attempts to make polycrystalline and ribbon silicon which are lower in cost than high-quality single crystals; but to date the efficiencies of these apparently lower-cost materials have been unacceptably small.
更近，有些人试图研制多晶硅和带状硅，这些材料比高质单晶硅成本小，但是，迄今为止，这些成本明显小的材料的效能低得不实用。
92. Although many scientists were aware of the very low cost of amorphous solar cells, they felt that they could never be manufactured with the efficiencies necessary to contribute significantly to the demand for electric power.
许多科学家虽然已经认识到非晶硅太阳能电池的低成本，但是他们也感到，要生产出这样的电池并使之产生足够的功效、在很大程度上满足对电能的需要，是不可能的。
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