Fabrication of CIGS solar cells with a Na-doped Molayer on a Na-free substrate

• DOI: 10.1016/j.tsf.2006.12.156
• Publication Date: 2006-12-21T15:14:16Z
• Authors: Jae Ho Yun; Ki Hwan Kim; Min Sik Kim; Byung Tae Ahn; Se Jin Ahn; Jeong Chul Lee; Kyung Hoon Yoon
• Keywords: Solar cells; Alumina substrate; CIGS; Na-doped Mo; 02 engineering and technology; 0210 nano-technology; 7. Clean energy

Abstract The photovoltaic properties of CIGS cells on an alumina substrate were improved through the use of Na-doped Mo as the bottom layer of a Mo back contact. Na was supplied to the CIGS bulk region from an alumina/Na-doped Mo/Mo structure, similar to the Na diffusion from soda-lime glass. The diffusion of Na from the Na-doped Mo was controlled effectively compared to that from Soda-lime glass (SLG). The present results indicate that Na-doped Mo acts as a Na source material and that the Na amount can be controlled by adjustment of thickness of Na-doped Mo layer, without the use of an alkali barrier layer. The highest conversion efficiency of 13.34% ( J sc = 34.62 mA/cm 2 , V oc = 0.58 V and FF = 66%) for an active area of 0.45 cm 2 on an alumina substrate was obtained for 100 nm Na-doped Mo/1000 nm Mo.