Effect of Na-Doped Mo/Mo Bilayer on Cigs Cells and its Photovoltaic Properties

The photovoltaic properties of CIGS cells on alumina substrate were improved by using the Na-doped Mo layer. The same as CIGS cells on soda-lime glass, Na was observed in the CIGS bulk region on Na-doped Mo/non-doped Mo/alumina substrate. The concentration of Na from Na-doped Mo was smaller than that from SLG. It means that Na-doped Mo might act as Na source and contents of Na could be controlled without alkali barrier layer. The best CIGS solar cell with conversion efficiency of 13.34, J_sc=34.62 mA/cm₂, V_oc=0.58 V and FF=66 % for an active area of 0.45 cm² on the alumina substrate was obtained at 100 nm Na-doped Mo/1000 nm Mo bi-layer