Formation of Cu2SnS3 nanoparticles by sequential injection of tin and sulfur oleylamine solutions into Cu1.8S nanoparticle dispersion

•Formation of crystalline Cu2SnS3 nanoparticles of ~8 nm in size.•Using Cu1.8S nanoparticles of ~6 nm in size as a copper source.•Sequential injection of tin and sulfur oleylamine solutions into a Cu1.8S nanoparticle dispersion.•Gelatinous amorphous Cu2SnS3 precursor as a transient intermediate.

The formation of Cu2SnS3 nanoparticles by using Cu1.8S as a copper source was investigated. X-ray diffractometry, Raman spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy were carried out for characterization. Injecting sulfur oleylamine solution into copper oleylamine solution at 220 °C produced a dispersion of Cu1.8S nanoparticles of ~6 nm in size. Thereafter, injecting tin oleylamine solution into the Cu1.8S nanoparticle dispersion at 220 °C produced gelatinous amorphous Cu2SnS3 precursor. The subsequent addition of sulfur oleylamine solution at 220 °C resulted in crystalline Cu2SnS3 nanoparticles of ~8 nm in size.