CdSe Colloidal Quantum Rings

TL;DR

This paper presents a novel heterostructure of CdS nanoplatelets with tunable CdSe rings, enabling continuous control over optical properties and emission wavelengths from 428 nm to 512 nm, bridging quantum dots and nanoplatelets.

Contribution

It introduces a one-pot synthesis method for CdSe rings on CdS nanoplatelets, allowing precise control over dimensionality and optical tuning.

Findings

Optical properties are tunable by structure thickness and ring width.

Emission wavelength range extended from 428 nm to 512 nm.

Dimensionality of CdSe can be tuned from 0D to 2D.

Abstract

Atomically flat semiconductor nanostructures have sharp photoluminescence emission, short radiative lifetimes and a well-defined planar structure. However, these nanostructures lack the optical and electronic fine-tuning that justify extensive research in colloidal quantum dots. Here, we propose a heterostructure based on CdS nanoplatelets with laterally grown CdSe. Samples of two different thickness and varying ring width are synthesized by a one-pot method during which CdSe ring width is controlled by Se precursor amount. The CdSe dimensionality is continuously tuned from a 0D array of CdSe dots to a 1D CdSe quantum ring and finally a 2D CdSe nanoplatelet. Sample characterization shows that their optical properties are tunable by both structure thickness and CdSe ring width. This continuous tunability extends the emission range of nanoplatelet-based structures from 428 nm to 512 nm for 3 and 4 monolayers structures.