Phase transitions have been investigated for silver deposition onto In2S3 precursor layers by spray chemical vapor deposition from a trimethylphosphine (hexafluoroacetylacetonato) silver (Ag(hfacac)(PMe3)) solution. The formation of Ag nanoparticles (Ag NPs) on top of the semiconductor layer set on concomitantwith the formation of AgIn5S8. The increase of the diameter of Ag NPs was accompanied by the evolution of orthorhombic AgInS2. The formation of Ag2S at the interface between Ag NPs and the semiconductor layer was observed. Surface photovoltage spectroscopy indicated charge separation and electronic transitions in the ranges of corresponding band gaps. The phase transition approach is aimed to be applied for the formation of plasmonic nanostructures on top of extremely thin semiconducting layers. (C) 2015 Elsevier B.V. All rights reserved.