Laser Scribing: a Key Enabling Technology for Manufacturing of Low Cost Thin Film Photovoltaic Cells

Solar cells are becoming a highly promising alternative energy source for various markets. In the last five years or so a tremendous amount of research effort has been put into increasing the efficiency of solar cell technology and reducing its manufacturing cost. It is believed that success in both of these areas will further propel its use in various markets. The two major structures commercially pursued for solar cell manufacturing are crystalline Silicon-based structure and thin film-based structure. Thin film technology includes amorphous silicon or cadmium telluride, CdTe, or copper indium diselenide, CIS or copper indium gallium diselenide, CIGS structures. From the manufacturing perspective thin film technology has a tremendous potential for achieving cost reduction by leveraging flat panel display (FPD) manufacturing infrastructure. Laser technology plays a key role in manufacturing of thin film solar cells by scribing the pattern at each of the three layers of the cell structure. At Spectra-Physics, we have developed laser-scribing process for each of the amorphous silicon thin film solar cell layers and have investigated ways to achieve maximum possible scribing speed. Laser scribing is a key enabling technology in reducing the cost of manufacturing of thin film solar cells.