Copper Indium diSelenide (CISe) and its derivative Copper Indium Gallium diSelenide (CIGSe) have gained increasing amounts of attention as materials for photovoltaic energy conversion. Recently CIGSe devices have proven to be able to produce power generation efficiencies exceeding 20% on the laboratory scale .
To increase the viability of CIGSe based devices there has recently been a push to decrease costs associated with the production of CISe/CIGSe solar cells through the utilization of Cu, In and Ga containing nanocrystals. Incorporation of nanomaterial based formation allows the utilization of solution based processing resulting in more scalable processes. One approach demonstrated by Guo et al investigates the incorporation of selenium into sulfide based CIGS (copper indium gallium disulfide) nanoparticles for grain growth to dense crystal structures with power generation efficiencies exceeding 10% .
Building off the work of Guo et al, the growth mechanisms of films from their respective Cu, In, and Ga containing nanoparticles are developed and shown. Work incorporates both in-situ and ex-situ experiments with the grain growth observed, and the applications of knowledge to other chalcopyrite based solar cells are discussed.
 M.A. Green, K. Emery, Y. Hishikawa, and W. Warta, “Solar cell efficiency tables (version 37),” Progress in Photovoltaics: Research and Applications, vol. 19, Jan. 2011, pp. 84-92.
 Q. Guo, G.M. Ford, H.W. Hillhouse, and R. Agrawal, “Sulfide nanocrystal inks for dense Cu(In1-xGa(x))(S1-ySe(y))2 absorber films and their photovoltaic performance.,” Nano letters, vol. 9, Aug. 2009, pp. 3060-5.