IRON PYRITE NANOCRYSTAL FILM AS A COPPER-FREE BACK CONTACT FOR POLYCRYSTALLINE CDTE THIN FILM SOLAR CELLS

摘要

The invention discloses nanocrystalline (NC) FeS₂ thin films as the back contact for CdTe solar cells. In one example, the FeS₂ NC layer is prepared from a solution directly on the CdTe surface using spin-casting and chemical treatment at ambient temperature and pressure, without a thermal treatment step. Solar cells prepared by applying the NC FeS₂ back contact onto CdTe yield efficiencies of about 95% to 100% that of standard Cu/Au back contact devices. In another example, FeS2 is interposed between Cu and Au to form a Cu/ FeS₂ NC/Au back contact configuration yielding an efficiency improvement of 5 to 9 percent higher than standard Cu/Au devices.