Papers by Author: Jae Ho Yun

Abstract: CuIn1-xAxlSe2(CIAS) films were obtained by selenization process of metallic precursors. The metallic precursors were deposited sequentially by using sputtering system. As the ratio of Al/(Al+In) in the precursors increased, the chalcopyrite (112) peak shifted to high value and the band-gap of CIAS layer increased to 1.38 eV. However, the bi-layer morphology with well crystallized large grain on the surface and small grain thin bottom layer was observed. Although the sequences of precursors were changed in order to get uniform layer, no distinguishable difference was not observed.

Abstract: Cu(In,Ga)3Se5 films were deposited on soda-lime glass substrate by three-stage co-evaporation process. In the film, the band gap increased as the Cu content decreased and also as the Ga content increased. The grain size became smaller as the Ga content increased. In the Cu1.29(In1-xGax)3Se5 system, the maximum hole concentration was 1x1015 /cm3 when the Ga content was 0.5 and its band gap was 1.45 eV. Comparing the conventional CIGS solar cell with Cu0.8(In0.7Ga0.3)Se2 film, the series resistance is too large, indicating that further p-type doping in the Cu(In,Ga)3Se5 film is necessary to improve cell efficiency for the top cell application in CIGS tandem solar cells.

Abstract: Silicone dioxide (SiO2) layer as an electrical insulator and diffusion barrier was deposited on a flexible stainless steel substrate by plasma enhanced CVD process. And we deposited Mo/Na-doped Mo bi-layer back contact on the oxide layer in order to supply Na into the CIGS absorber. Then we deposited CIGS layer by three-stage process using elemental co-evaporation method and completed the solar cell fabrication. Without antireflection coating, the best CIGS solar cell on the stainless steel showed the conversion efficiency of 10.57 % with Jsc = 33.38 mA/cm2 and Voc = 0.519 V and FF = 0.61 for an active area of 0.45 cm2.