Synthesis of colloidal SnSe quantum dots by electron beam irradiation

Water-soluble orthorhombic colloidal SnSe quantum dots with an average diameter of 4 nm were successfully prepared by a novel irradiation route using an electronic accelerator as a radiation source and hexadecyl trimethyl ammonium bromide (CTAB) as a surfactant. The quantum dots exhibit a large direct bandgap of 3.89 eV, greatly blue shifted compared with that of bulk SnSe (1.0 eV) due to the quantum confinement effect. The quantum dots show blue photoluminescence at ∼420 nm. The influence of CTAB on the growth of the quantum dots was investigated and a possible reaction/growth mechanism was proposed.

► A rapid, facile and green strategy is developed to synthesize SnSe QDs.
► The raw materials are green and easily obtained.
► The surfactant CTAB plays an important role in the formation of SnSe quantum dots.
► The obtained SnSe QDs is well-dispersed with the average size of around 4 nm.