Colloidal Single Layer Quantum Dots with Lateral Confinement Effects on 2D Exciton.
Controlled lateral quantum confinement in single layer transition metal chalcogenides (TMCs) can potentially combine the unique properties of two dimensional (2D) exciton with the size tunability of exciton energy, creating the single layer quantum dots (SQDs) of 2D TMC materials. However, exploring such opportunities has been challenging due to the limited ability to produce well defined SQDs with sufficiently high quality and size control, in conjunction with the commonly observed inconsistency in the optical properties. Here, we report an effective method to synthesize high quality and size controlled SQDs of WSe2 via multilayer quantum dots (MQDs) precursors, which enables grasping a clear picture of the role of lateral confinement on the optical properties of the 2D exciton. From the single particle optical spectra and polarization anisotropy of WSe2 SQDs of varying sizes in addition to their ensemble data, we reveal how the properties of 2D exciton in single layer TMCs evolve with increasing lateral quantum confinement.
Journal of the American Chemical Society