Selenization of CIGS Films with Different Cu-In-Ga Alloy Precursors

CIG precursors were deposited on the glass from the Cu-Ga alloy and Indium targets by co-sputtering method. The results show that when the sputtering pressure was increased, the surface morphology was changed from a roughness island-crystalline (RMS=165 nm) to a smaller pellet-crystalline (RMS=54.4 nm). At the same time the Cu/(In+Ga) ratio was increased. So, the crystallization of Cu11In9 phase was increasing and CuIn2 phase was decreasing in the CIG precursor. Then, a layer of selenium was coated on the precursor and the precursor was selenized using RTA selenization of 600 °C. The results show a good stoichiometric and crystallization under the parameters of the sputtering pressure at 4.2 mTorr of CIG precursors.