| 초록 |
Recently kesterite based Cu2ZnSn(S,Se)4 (CZTSSe) photo absorber materials have been widely studied for thin film solar cells application. They exhibit low cost, nontoxic and earth abundant elements which makes them superior that of CIGS. Although the CIGS based solar cell reached over 20% device efficiency, the CZTSSe based solar cell still exhibits highest device efficiency of 12.6%. To overcome this performance gap, it is necessary to improve each constituting layer properties from the solar cell. Among them, the window layer which one the important part of the solar cell must exhibit high transparency and good electrical characteristics. It helps to transmit maximum light towards the absorption layer and efficient charge transfer in the solar cell. The most commonly used window/transparent conducting electrode (TCO) material to date is Aluminum (Al) doped ZnO (AZO). Further, to improve further device efficiency it is necessary to improves AZO properties. However, improving the properties of ZnO through doping of single element has the disadvantage of improving only one property. To solve this problem, we studied synergistic effect of Al and Fluorine (F) doping properties to improve the multiple properties at the same time. Among them, F can provide additional donners by replacement of the oxygen atom and there by improvement in electrical properties. Moreover, provide high transmittance in the long wavelength region and carrier mobility. In this study, F was added to AZO to evaluate the characteristics of the thin film, and the effect on the solar cell parameters was analyzed by applying it to the CZTSSe solar cell. |
