Environmental-friendly and visually appealing Cu(In,Ga)$Se_2$ thin-film photovoltaics by tuning electrical and optical properties of front layers

Abstract

Recently, as urbanization accelerates and the demand for energy self-sufficiency increases, the need for photovoltaic modules applicable to buildings is expanding. Among various solar cells, a Cu(In,Ga)$Se_2$ (CIGS) thin-film solar cell is attracting the most attention because of their high efficiency, flexibility, stability, and cost competitiveness. In this thesis, several methods and results for the fabrication of environmentally friendly and aesthetically superior CIGS thin-film solar cells are presented. The buffer layers are fabricated with novel materials and methods for non-toxic CIGS solar cells. In addition, for replacing the conventional metal grid electrode, inconspicuous metal microfiber with a very high electrical conductivity is applied to achieve high efficiency. Finally, the optical path lengths of the transparent electrode layer and the buffer layer are varied to control optical light interference, thereby implementing various colors of the solar cell with minimized current loss.