Related Experiment Video
Updated: Jun 23, 2026

Compact Quantum Dots for Single-molecule Imaging
Published on: October 9, 2012
Not all silicon quantum dots are equal: photostability of silicon quantum dots with and without a thick amorphous
I Teng Cheong1, LiYifan Yang Szepesvari1, Chuyi Ni1
1Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada. jveinot@ualberta.ca.
Abstract:
Luminescent colloidal silicon quantum dots (SiQDs) are sustainable alternatives to metal-based QDs for various optical applications. While the materials are reliant on their photoluminescence efficiency, the relationship between the structure and photostability of SiQDs is yet to be well studied. An amorphous silicon (a-Si) shell was recently discovered in SiQDs prepared by thermally-processed silicon oxides. As a-Si is known as a source of defects upon UV irradiation, the disordered shell could potentially have an adverse effect on the optical properties of nanoparticles. Herein, the photostability of ∼5 nm diameter SiQDs with an amorphous shell was compared with that of over-etched SiQDs of equivalent dimensions that bore an a-Si shell of negligible thickness. An UV-induced degradation study was conducted by subjecting toluene solutions of SiQDs to 365 nm light-emitting diodes (LEDs) under an inert atmosphere for predetermined times up to 72 hours. The structure, composition, and optical responses of the exposed SiQDs were evaluated.
Related Concept Videos
Atomic Structure
Subatomic Particles
The Uncertainty Principle
Nuclear Stability
To hold positively charged protons together in the...
Atomic Structure
Equilibrium Conditions for a Particle
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...

