Electro/electroless deposition and characterization of Cu-In precursors for CIS (CuInSe2) films

Cu-In (CI) precursors for growing CuInSe2 (CIS) thin films were deposited and characterized. CI precursors were formed by using electrodeposition and electroless methods. In electrodeposition, CI precursors were formed by sequential deposition of Cu/In and In/Cu. In electroless deposition, the CI precursor was formed by co-deposition. The CI precursors were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Initial results on the selenization of the precursors indicated that Cu-m (electroless), Cu/In and In/Cu configurations are suitable for forming device quality CIS films. The major phases in the precursors were found to be Cu11In9 and elemental In, which may lead to the formation of the In-rich CIS phase (CuIn2Se3.5, JCPDS 35-1349) during sintering in argon at lower temperatures. It was found that the stoichiometric CIS phase (CuInSe2, JCPDS 40-1487) is formed by selenization of the precursors at temperatures higher than 500 degrees C.