Synthesis and characterization of metal thiocarboxylates: Potential single-source precursors for metal sulfides

Abstract

The aim of this thesis is to synthesize suitable metal thiocarboxylates as single molecular precursors for making metal sulfide powders, thin films and nanocrystals which find applications in photovoltaic, optoelectronic devices, and optical materials.Of the lanthanides thiocarboxylates prepared [Ln(2,2'-bpy)(SC{O}Ph)3(H2O)].Et2O (Ln = La, Pr and Sm) have been found to retain Et2O (b.p. 34.6oC) above 51-82oC, while [Ln(2,2'-bpy)2(SC{O}Ph)3] (M = La, Pr, Yb) serve as precursors for Ln2O2S. Further [Mg{In(SC{O}Ph)4}2] and [Ca(H2O)x{In(SC{O}Ph)4}2].yH2O (x & y = 0-2) have been found to furnish MgIn2S4 and CaIn2S4 at ~600 oC. Thin films of La2S3 and MoS2 were obtained from [La(bipy)(S2CNEt2)3] and [Mo2(SC{O}Me)4(PPh3)2] by chemical vapor deposition methods. Further high temperature orthorhombic phase AgInS2 nanocrystals obtained from [(Ph3P)2AgIn(SCOPh)4] using a mixture of surfactants show significant third order non-linear optical properties. Finally Bi2S3 nanomaterials having interesting morphologies were synthesized by various methods.