PREPARATION OF COPPER INDIUM SULFIDE THIN-FILMS BY SINGLE-SOURCE OMCVD - MASS-SPECTRAL INVESTIGATION OF DECOMPOSITION PATH OF THE ORGANOMETALLIC SOURCES

In order to prepare high-quality CuInS2 thin films vapor phase decomposition patterns of three copper-indium binuclear complexes, Bu2In[S(i-Pr)]Cu(S2CNBu2) (1a) BuIn[(i-Pr)]Cu(S2CNBu2) (1b) and Bu2In[S(i-Pr)]Cu[S2CN(i-Pr)2] (1c) as candidates for source materials were investigated using El MS. The complex 1c showed series of intensive peaks due to the fragmentation of M+. For 1a, only a fragmentation pattern starting from BuIn(S2CNBu2)2 was detectable. This should suggest that la decomposed into BuIn(S2CNBu2), and copper sulfide before vaporization. In addition an ambiguous feature could be observed for lb, viz. two fragmentation paths. Consequently, we judge that 1c is a suitable source complex to prepare CuInS2 thin films via a single-source OMCVD process. Thus chalcopyrite CuInS2 thin films were successfully prepared via single-source OMCVD using 1c as a source complex, with T(substrate) 400-degrees-C, T(source) 80-degrees-C, base pressure 0.7 Torr and carrier (nitrogen) flow rate 0.8 L min-1. Fragmentation of two copper dithiocarbmates, Cu(S2CNBu2)2 and Cu[S2CN(i-Pr)2]2, and two butylindium thiolates, Bu2InS(i-Pr) and BuIn[S(i-Pr)]2, as components of 1 is additionally discussed.