CIG and CIGS Products
SMI now has a new line of casted rotatable and planar targets for the thin film solar industry. Casted targets offer high density (99%+) material that enable thin film technicians greater control and better material utilization. Materials can be casted to rotatable targets up to 50” in length. Thin film deposition with low density material, such as powder based metallurgy and cold spray create low density target material that is prone to arcing and contamination in process. Casting the ternary alloy CuInGa has proven very difficult because of it’s unique properties and complicated phase transitions. Normal casting techniques yield segregated material prone to contamination by cast forms and other casting equipment.
About The Technology
With over 3 years of research and development invested in creating a process for casting CIG and CIGS onto planar and rotatable backplates, casted targets are now available. Casted targets are now available through SMI’s patent pending casting services. This new innovative casting technology also works with high purity materials such as In, InSn, Sn, Zn, Al, SAC, and others. The nature of high density and high purity material lends itself to be cleanly reclaimed and re-casted into new targets.
Why Casted Targets?
Casted targets enable a high level of total material utilization, because of the increased density, target life and control are extended as well as be reclaimed and reused to make new targets. There is a significant difference between powder metallurgy targets and casted CIGS targets; casted target processes can reuse the spent material, literally machining clean material off spent targets and re-casting it to make new targets.
Determining the optimal economic cost model for quality materials is vital for producing competitively priced solar cells. The optimal use of material must include cost effective reclaim of spent targets. Casted targets enable a high level of total material utilization, because of the increased density, target life and control are extended as well as be reclaimed and reused to make new CIG targets.
Powder metallurgy may employ a number of fabrication techniques such as cold spray or pressing, which may or may not include sintering. For powder based CIG targets, the spent material must be reclaimed to make new CIGS powder for the fabrication process. Powderizing very soft metals such as Indium and Gallium can be difficult and prone to introducing contamination depending on the methodology. Powder must be sifted into the proper size which is another point of potential contamination. Those particle sizes that are not the right size are sent back for remelt and re-powderized. These additional steps add cost to material, unlike melting the spent target material for casting. Both casting and powder based targets have a fabrication cost, however, casting has the advantage of reusing spent target material more cost effectively.