11percnt; efficient singlehyphen;crystal solar cells and 10percnt; efficient polycrystalline cells made from refined metallurgical silicon

摘要

Refined metallurgical silicon has been utilized as a feedstock material both for Czochralskihyphen;pulled single crystal and for cast polycrystalline silicon solar cells. Using a phosphorous diffused junction for annonpstructure, the singlehyphen;crystal cells have yielded AM1 efficiencies up to 11.1percnt;, open circuit voltages up to 596 mV, and fill factors as high as 81percnt; (not all on the same cell). The cast polycrystalline substrates have produced cells up to 10.1percnt; efficient (AM1) with fill factors of 79percnt; andVoc= 585 mV. Properties of the singlehyphen;crystal and polycrystalline cells are quite similar, with the principal limiting factor beingJsc, which is typically 20ndash;23 mA/cm2. Spectral response and EBIC data indicate that a considerable amount of the recombination is due to impurities. For the cast polycrystalline cells, the electron beam induced current data shows that grain boundary recombination is significant.