CdSe@CdS Dot@Platelet Nanocrystals: Controlled Epitaxy, Mono-Exponential Decay of Two-Dimensional Exciton, and Non-Blinking Photoluminescence of Single Nanocrystal

摘要： Wurtzite CdSe@CdS dot@platelet nanocrystals—a dot-shaped CdSe nanocrystal encased within an epitaxially-grown CdS nanoplatelet—are controllably synthesized with nearly monodisperse size/shape distribution and outstanding photoluminescence (PL) properties. The excellent size/shape control with their lateral to thickness dimension ratio up to 3 to 1 is achieved by systematically studying the synthetic parameters, which results in a simple, tunable yet reproducible epitaxy scheme. This special type of core/shell nanocrystals possess two-dimensional emission dipole with the ab plane of the wurtzite structure. While their near-unity PL quantum yield and mono-exponential PL decay dynamics are at the same level of the-state-of-art CdSe/CdS core/shell nanocrystals in dot shape, CdSe@CdS dot@platelet nanocrystals possess ~2 orders of magnitude lower probability for initiating PL blinking at single-nanocrystal level than the dot-shaped counterparts do.