An overview on electrodeposited Cu(In,Ga)(Se,S)2 thin films for photovoltaic devices

Industrial implementation of Cu(In,Ga)(Se,S)(2) (CIGS) solar cells based technologies is usually based on two vacuum deposition techniques: thermal evaporation and sputtering. Despite the ability to produce high purity and high efficiency solar cells with reasonable reproducibility, they exhibit some limitations with respect to their suitability for high-throughput and large area manufacturing and a better materials using rate that would in turn reduce production costs. The sophisticated vacuum equipment requires high capital investment, decreases the flexibility to implement changes and thus it is more vulnerable to predict the desired results. The compositional control that is required in CIGS solar cells in particular is difficult to maintain during up scaling to large area modules by means of vacuum methods. Implementation of a roll-to-roll process with the use of large, flexible substrates to decrease processing time and increase throughput would further raise the desire of cost effective and fast non-vacuum processes that omit pumping times and are inherently easy to up-scale. The historical developments and main advantages of CIGS thin film photovoltaic devicesis revised and costs considerations are argued to support the interesting approach of electrodeposition as a preferred technique for industrial CIGS substituting sputtered precursors.