Large grain (112) oriented CuInSe2 thin films grown by R.F. sputtering

(112) oriented CuInSe2 thin films with grain size larger than 30 microns have been grown by magnetron RF sputtering on a glass substrate covered by a crystalline thin metalic layer obtained by a novel method. The CuInSe2 targets have been prepared by melting Cu, In, and Se in a high-pressure furnace using B2O3 as an encapsulant. The structural and electro-optical properties of CuInSe2 films have been found to depend on substrate temperature, sputtering power, substrate bias, target stoichiometry, and deposition rate. CuInSe2/CdS solar cells prepared by flash-evaporating CdS on top of RF-sputtered CuInSe2 films have so far exhibited high photocurrents, close to 40 mA/cm2 at 100-mW/cm2 illumination, and a maximum efficiency close to 4 percent.