GROWTH OF HIGH-QUALITY CUINSE2 FILMS BY SELENISING SPUTTERED CU-IN BILAYERS USING A CLOSED GRAPHITE BOX

High-quality CuTnSe(2) thin films have been prepared using a two-stage process. Multiple bilayers of Cu and In were deposited onto Mo-coated glass substrates by magnetron sputtering to produce a predominant Cu1 1In9 phase, and the layers were selenised using elemental selenium in a closed graphite box at different temperatures in the range of 250-55 0 degrees C. The films were characterised to evaluate their physical b ehaviour by X-ray diffractometry, scanning electron microscopy and ene rgy dispersive X-ray analysis. Polycrystalline and single-phase CuInSe 2 films with a strong (112) preferred orientation were obtained at an annealing temperature of about 500 degrees C. These layers were unifor m, and the crystals were densely packed with a grain size of about 2.0 mu m. At lower annealing temperatures, the presence of different bina ry phases of Cu-In, Cu-Se and In-Se were observed in the films. It was found that these binary phases react with each other, resulting in th e formation of the ternary CuInSe2 phase. (C) 1998 Elsevier Science B. V. All rights reserved.