Development of Ultra Thin Metal Substrate for use in CIGS Solar Cells
Group of researchers at AIST and Toyo Kohan Co., Ltd has successfully developed a low-cost metal substrate for ise in CIGS solar cells offering a 16% conversion efficiency. The new metal uses low carbon steel as the base, providing a low-cost alternative to stainless steel foil. CIGS solar cells offer the highest conversion efficiency among the thin film solar cells and are expected to be used as the post-crystalline silicon solar cell.
The metal substrate is a replacement to conventional glass substrate for use in flexible solar cell modules for various applications of the modules, including BIPV (Building Integrated Photovoltaic). Titanium and molybdenum sheets has been previous used previously as metal substrate in this application of flexible solar cell, but such materials lack good cost performance. In this development Toyo Kohan brings its know how in both cold rolling and surface treatment of ultra-thin steel sheets, allowing the manufacturing of ultra-thin (less than 100 micro meter) and width of 500 to 1000mm sheets of surface treated steel, which is necessary for the substrate of flexible CIGS solar cells. Toyo Kohan is aiming for commercialization of the newly developed metal substrate sometimes around 2011.