Synthesis of ln2S3 nanoplates and their self-assembly into superlattices

Ultrathin nanoplates of beta-phase semiconductor ln(2)S(3) with the diameter of 50 similar to 80 nm and a thickness of 1.85 nm were synthesized via a simple hot injection solution method with Hexadecylamine (HDA) as ligand, and the nanoplates self-assembled into superlattices by face to face stacking during evaporation of the solvent. The nanoplates and the assembled superlattices were characterized by XRD, TEM, HRTEM, XPS etc. The TEM and XRD results display that the nanocrystals are highly crystalline, hexagonal shape, and uniform in thickness. A strong quantum confinement effect of the 2D nanoplates was observed from the UV-Vis and PL spectra for the first time in the ln(2)S(3) nanoplates. A possible mechanism of the synthesis and assembly was proposed.