Fraunhofer Institute for Solar Energy Systems (ISE) of Germany achieved an energy conversion efficiency of 23.4% with a single-crystal silicon solar cell made by forming a thin p-type semiconductor layer on an n-type semiconductor substrate.
Its cell area is 2 x 2cm. Fraunhofer ISE said that it is possible to mass-produce the solar cell, which is one of the most efficient crystalline silicon solar cells and could rival Sanyo and other companies' products.
Crystalline silicon solar cells based on n-type semiconductor substrates have a higher resistance to impurities than those based on p-type semiconductor substrates. Therefore, it is theoretically easier to enhance the energy conversion efficiency of the former solar cells.
However, most of the crystalline silicon solar cells developed so far are based on p-type semiconductor substrates. Specifically, they are made by forming a thin n-type semiconductor layer on a thick p-type semiconductor.
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