The shape evolution process of two-dimensional CdSe nanocrystals altered by seed concentration

Abstract

Two-dimensional (2D) nanocrystals have attracted considerable attention for their exceptional optical, electrical and catalytic properties. But the formation mechanism of 2D nanocrystals remains debatable. Shape evolution can provide a platform for a more accurate and complete understanding of the formation mechanism of 2D nanocrystals. In this work, we used purified CdSe quantum dots as seeds to grow 2D nanocrystals. The shape of the CdSe 2D nanocrystals can change from rectangular 2D nanocrystals to square 2D nanocrystals with increasing growth time. This shape evolution process can be adjusted by the addition of different concentrations of CdSe seeds. Upon reducing the concentration of CdSe seeds, the shape evolution process of CdSe 2D nanocrystals was accelerated. The dissolution and recrystallization behaviors play a key role in the shape evolution of CdSe 2D nanocrystals.