| 초록 |
Cu(In,Ga)Se2 (CIGS) precursor thin films have been prepared onto Mo coated glass substrates by electrodeposition at room temperature with various quantities of gallium (III) nitrate hydrate (Ga(NO3)3 • xH2O) from 16ml to 32ml. The electrolytic bath used contains copper (II) chloride (CuCl2), indium (III) chloride (InCl3), gallium (III) nitrate hydrate (Ga(NO3)3 • xH2O), selenous acid (H2SeO3), lithium chloride (LiCl), and C8H5KO4. The pH of electrolytic bath solution was adjusted to 2.2 by adding diluted HCl. The as-deposited CIGS precursors were annealed in H2S atmosphere in order to introduce S element in the CIGS thin films. The effects of Ga(NO3)3 • xH2O quantity on the structural, morphological, and compositional properties of CIGS thin films were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), raman spectroscopy, field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS), respectively. XRD, TEM and Raman studies showed that the as-deposited CIGS precursor thin film was synthesized as an amorphous structure. However, the after sulfurized thin films were grown as a tetragonal structure without secondary phase. FE-SEM image showed that morphology of as-deposited CIGS precursor thin films were rougher with increasing Ga quantity. UV- VIS spectroscopy studies showed that the absorption coefficient were over 10-4 and band gap energy increased with increasing Ga quantity. A cell efficiency of 2.15 % (Voc : 564 mV, Jsc : 8.663 mA/cm2, FF : 0.44) was obtained using Al/Al doped ZnO/i-ZnO/CdS/CIGSS/Mo/glass multi-layered structure. |
