Fabrication of high efficiency CuIn(Ga)Se/sub 2/ thin film solar cell by of high efficiency selenization with H/sub 2/Se

Effects of preparation conditions for precursors in selenization with H/sub 2/Se on film properties of CuInSe/sub 2/ and CuIn/sub 1-x/Ga/sub x/Se/sub 2/ were studied. Using a Cu/In stacked layer precursor prepared at temperature of 200 C, grain sizes for selenized CuInSe/sub 2/ films became as large as 2 /spl mu/m. It was found from XRD analysis that MoSe/sub 2/ was formed at the boundary to the Mo back electrode for a selenization process using the stacked layer precursors. Formation of MoSe/sub 2/ was suppressed using a Cu-In-Se mixed compound precursor. Grain sizes for selenized CuInSe/sub 2/ films with Cu-In-Se precursors prepared at 200 C were about 1 /spl mu/m. A glass/Mo/CuIn(Ga)Se/sub 2CdZnS/ZnO cell structure was fabricated to study the effects of the precursor on cell performances. It was found that Voc was improved for Cu-In-Se precursors as substrate temperature increased. A fill factor exceeding 0.7 was obtained using Cu-In-Se precursors prepared at 200 C. A value of Voc was improved with Ga doping near the boundary to the Mo back electrode. Using Se mixed precursors, conversion efficiencies of 12.6% and 11.7% were obtained for CuInSe/sub 2/ solar cells and CuIn/sub 1-x/Ga/sub x/Se/sub 2/ solar cells.<
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