Synthesis and characterization of water-based CIGS ink for photovoltaic applications

Abstract

Due to their many benefits, CIGS (Copper Indium Gallium Selenide, CuInxGa(1−x)Se2) based solar cells are preferred over their alternatives for powering different systems in space applications. The current methods for synthesizing the CIGS thin films are expensive and complicated due to the use of vacuum and/or involvement of high temperatures and a multi-step approach involving a separate selenization step. Ink-jet printing is considered as a simple and affordable process to deposite thin films, which require materials in the ink (particulate dispersion) form. Thus, the presented work focuses on synthesizing a printable CIGS ink using a solution processing route at room temperature without a vacuum environment. The synthesis of CIGS ink is done from a chemical bath containing the ions of its constituents, followed by the addition of a strong reducing agent and continuous, vigorous stirring. An analysis of X-ray diffraction verified the existence of the CIGS crystal structure. With the help of UV–visible spectroscopy, the band gap of the ink was calculated using the Tauc plot method, while morphological studies were done using FESEM and AFM. This effort will contribute to developing an easy-to-use, low-cost method for the continued development of CIGS ink.Graphical