Single-source approach for the growth of I-III-VI thin films

Abstract

The ternary chalcopyrite semiconductors I-III-VI are currently used for photovoltaic solar cell applications. In this study, AgIn5S8 thin films were prepared from a series of single-source bimetalorganic precursors, e.g. [(PPh3)2AgIn(SC{O}R)4] (R = alkyl) by aerosol assisted chemical vapour deposition (AA-CVD). The compounds can be used as single-source precursors for the deposition of ternary compounds (I-III-VI) by one-pot reaction using CVD process and they are found to be air stable, which is favourable in comparison with metal alkyl compounds, which are found to be pyrophoroic. The optimum growth temperature for the preparation of these films on glass and Si(100) substrates, was found to be above 350 °C in terms of crystallinity, although deposition occurred at low temperatures. The films have been investigated using XRD, SEM and EDS. SEM analysis shows that all films are microcrystalline but have different morphologies depending on the growth temperatures. XRD results show evidence of the crystalline nature of these films. The results of this comprehensive study are presented and discussed.