Thin-film solar cells based on chalcopyrite semiconductor Cu(In,Ga) (S,Se)2 compound (hereafter called CIGS or CIGSeS irrespective of the exact composition) have continuously drawn interest because of their progressively increasing high photovoltaic conversion efficiencies and the merits of long-term performance stability, high energy yield, low cost production potentials and other advantages for industrial manufacturing and application of solar.