Tribenzoylarsine – A Benign Arsenic Precursor for InAs Nanocrystals

III-V semiconductor nanocrystals (NCs) have emerged as a benign alternative to II-VI and IV-VI NCs, which are restricted due to the toxicity of the comprising elements. While InP NCs advanced significantly, the development of infrared-emitting InAs NCs has been relatively slow-paced. This is due to the synthetic challenges arising from the highly covalent bonding in InAs and the limited range of available arsenic sources. Most importantly, current syntheses rely on hazardous pyrophoric and costly reagents, which hampers their wider adoption. In this work, the synthesis of tribenzoylarsine is reported, which can be used as a novel nonvolatile, nonpyrophoric, and hence safer precursor for metal arsenide nanoparticles. Tribenzoylarsine reacts with indium oleate without additional reducing agents yielding small (≈2 nm) InAs NCs. By tuning synthesis parameters (e.g., the addition of zinc oleate or using continuous injection) it is possible to cover the photoluminescence range of 630-780 nm with full width at half maximum as low as 170-210 meV, which is a very competitive value to the existing synthetic approaches. Along with the significantly safer nature of tribenzoylarsine and the great potential for synthesis optimization, this makes it a very promising alternative to the currently used arsenic precursors.