Facile, Economic and Size-Tunable Synthesis of Metal Arsenide Nanocrystals

Abstract

Synthesis of colloidal nanocrystals (NC) of important arsenide nanomaterials (e.g., InAs, Cd3As2) has been limited by the lack of convenient arsenic precursors. Here we address this constraint by identifying a convenient and commercially available As precursor, tris-dimethylaminoarsine (As(NMe2)3), which can be used to prepare high quality InAs NCs with controlled size distributions. Our approach employs a reaction between InCl3 and As(NMe2)3 using diisobutylaluminum hydride (DIBAL-H) to convert As(NMe2)3 in situ into reactive intermediates AsHx(NMe2)3–x, where x = 1,2,3. NC size can be varied by changing DIBAL-H concentration and growth temperature, with colloidal solutions of InAs showing size dependent absorption and emission features tunable across wavelengths of 750 to 1450 nm. We also show that this approach works well for the colloidal synthesis of Cd3As2 NCs. By circumventing the preparation of notoriously unstable and dangerous arsenic precursors (e.g., AsH3 and As(SiMe3)3), this work improves th...