Abstract(inEnglish).PDF

Abstract (in English) Recently, solar energy has drawn much attention due to the development of renewable energy. Various solar cells have been widely studied for the application of solar energy to replace the conventional power for terrestrial application, including single/multi junction GaAs, crystalline Si cells (single/ multi crystalline), thin film technologies (CIGS, CdTe, amorphous-Si), and other emerging technologies. In this dissertation, the main research focus is on CIGS thin film technology. We have developed a simplified fabrication process and investigated the characteristics of CIGS solar cells prepared by the one-step sputtering process. In the first topic of this dissertation, we demonstrated the feasibility of one-step sputtering process for the fabrication of CIGS absorbers. By using pulse DC sputtering from a single quaternary CIGS target, the chalcopyrite structure is spontaneously developed on the substrate at 500 oC even without extra Se supply. The obtained CIGS absorber layer possesses unique columnar grains with (112) preferred orientation, which is quite different from those prepared by co-evaporation process. In addition, the characterization of one-step sputtered CIGS films and devices were also addressed. The best efficiency of 8.22 % was achieved at the 2 area of 0.4 cm with open circuit voltage (Voc) of 505 mV, short circuit 2 current density (Jsc) of 24.76 mA/cm and the fill factor (FF) of 0.66 by using a nearly stoichiometric CIGS target. The second topic of this dissertation focuses on the target composition effect on the CIGS films and devices. By tuning the composition of CIGS targets, we modified the film composition from Cu-rich to slight Cu-poor. In addition, the Cu2-xSe second phase was suppressed by using a modified CIGS target. Even no KCN tre