Arsenic Silylamide: An Effective Precursor for Arsenide Semiconductor Nanocrystal Synthesis

The synthesis of metal arsenide semiconductor nanocrystals is challenging compared to other conventional materials (e.g., II-VI family CdSe) due to a high degree of covalency in crystal lattice and a lack of a variety of effective pnictide precursors. We reported here the use of [(Me3Si)(2)N](2)AsCl (arsenic silylamide) to synthesize a variety of binary and tertiary quantum confined species such as InAs (III-V), Cd3As2 (II-V), and Cu3AsS4 (enargite, I-3-V-VI4) nanocrystals. The physical properties of this reagent resolve many issues, especially concerning safety, with other precursors such as pyrophoric (TMS)(3)As and highly toxic AsH3 gas. Furthermore, usage of this reagent has allowed for the realization of enargite quantum rods for the first time. The role of arsenic silylamide in the reaction mechanism to form InAs has been elucidated with a combination of NMR spectroscopy as well as quantum chemical modeling. Cd3As2 and Cu3AsS4 nanostructures form via a diffusion mechanism.