A COMPARATIVELY LOW-QUALITY SILICON MATERIAL IMPROVED FOR SOLAR-CELL FABRICATION

A comparatively low-quality silicon wafer (with a purity of almost-equal-to 99.9%) was adopted to form a silicon-on-defect-layer (SODL) structure featuring improved crystalline silicon near the defect layer (DL) by means of proton implantation and subsequent annealing. Thus, the SODL technique provides an opportunity to enable low-quality silicon wafers to be used for fabrication of low-cost solar cells.

35-PERCENT EFFICIENT NONCONCENTRATING NOVEL SILICON SOLAR-CELL

An energy conversion efficiency of 35% was obtained at 1-sun, air mass 1.5 for a novel silicon cell having an area of 2.3 X 2.3 mm2 . cell. The critical feature of the cell structure is the inclusion of local defect layers near a p-n junction. The local defect layers were proven to hold the key to achieving the exceptionally high efficiency of the novel cell fabricated via noncomplex processing.