7.3% efficient CuInSe/sub 2/ solar cell

A 7.3%, 3.3 cm/sup 2/ active area efficient ZnO/thin CdS/CuInS/sub 2/ solar cell is demonstrated with 22.7 mA/cm/sup 2/ J/sub sc/, 592 mV V/sub oc/, and 0.546 fill factor. X-ray diffraction shows that the CuInS/sub 2/ films with are predominantly randomly oriented chalcopyrite CuInS/sub 2/ with additional minor phases such as In/sub 2/S/sub 3/ and Cu/sub 2-x/S present. Optical transmission and reflection data for CuInS/sub 2/ films on glass are also shown. Optical transmission implies a 1.4-eV bandgap, less than the 1.55-eV bandgap for single-crystal CuInS/sub 2/, but consistent with other reported thin-film results. It is concluded that the resolution of several materials, device, and fabrication issues will result in efficiencies of greater than 15%.<<ETX>>