Single Source Precursors for Calcium Sulfide (CaS) Deposition

Abstract

Here we describe preliminary studies into the synthesis structural characterisation and thermal properties of a family of calcium xanthate precursors for application in the deposition of CaS thin films. The straightforward, low‐temperature syntheses are detailed along with characterisation of the resulting compounds by 1H and 13C NMR and elemental analysis. Solid state molecular structures of all compounds, obtained from single‐crystal X‐ray diffraction, are presented and discussed in detail. The decomposition behaviour of the precursors has been probed through TGA, TGA‐MS and thermal annealing experiments, indicating that the compounds decompose cleanly into CaS.

Dithiocarbamate Complexes as Single Source Precursors to Nanoscale Binary, Ternary and Quaternary Metal Sulfides

“…Synthetic routes to these materials are being developed and one approach is the use of SSPs. 534 In the mid-1990s, Purdy and George described the synthesis of a range of calcium DTC complexes, [Ca(S 2 CNR 2 ) 2 ], including those derived from primary amines, together with the strontium complex, [Sr(S 2 CNBu 2 ) 2 ], from reactions of [M-(NH 2 ) 2 ] with CS 2 in the presence of secondary amines. 535 TGA showed that disubstituted complexes decompose at high temperatures (350−400 °C) to give highly carbonized CaS, and [Sr(S 2 CNBu 2 ) 2 ] has a similar decomposition profile to afford SrS.…”

“…Consequently, as a result of their high QYs and resistance to photobleaching, thin films of lanthanide-doped calcium sulfide nanomaterials show potential as fluorescent materials for displays, imaging and solar spectral conversion. Synthetic routes to these materials are being developed and one approach is the use of SSPs …”

Chemistry of alkaline earth metals: It is not all ionic and definitely not boring!

“…Molecular seven-coordinate calcium compounds have recently been synthesized as precursors for e.g. CaS, which is among the alkaline earth sulfides (MgS, CaS, SrS, BaS) that are interesting materials for emissive layer matrices in thin-film electroluminescent displays when doped with other elements [72]. Xanthate complexes can be stabilized with neutral donor ligands like ethanol, N,N,N 0 ,N 00 ,N 00 -pentamethyldiethylenetriamine (PMDTA) or substituted pyridines, and the coordination geometries reach from (distorted) pentagonal bipyramidal to distorted capped prismatic (Fig.…”

“…Heptacoordinated calcium xanthate compounds with pyridine-derived co-ligands can act as precursors for CaS (with permission from[72]). Disila polyether complexes with Ca 2+ , Sr 2+ and Ba 2+ (adapted with permission from[73]).…”

A chemist's guide to photoelectrode development for water splitting – the importance of molecular precursor design

“…193 Using different precursors simultaneously does, however, lead to complications associated with differing thermal decomposition rates and temperatures, solubilities and volatilities, and different film deposition mechanisms leading to varied growth rates; all of which will contribute towards non-homogeneous and nonstoichiometric deposition. 218,255,256 While stoichiometries can be improved by trial-and-error depositions to find the right precursor ratio, non-homogeneous deposition can only be fixed by using more compatible precursors with similar pertinent properties.…”