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Updated: May 13, 2026
Compact Quantum Dots for Single-molecule Imaging
Published on: October 9, 2012
Controlled placement of colloidal quantum dots in sub-15 nm clusters
Vitor R Manfrinato1, Darcy D Wanger, David B Strasfeld
1Electrical Engineering and Computer Science Department, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
Abstract:
We demonstrated a technique to control the placement of 6 nm-diameter CdSe and 5 nm-diameter CdSe/CdZnS colloidal quantum dots (QDs) through electron-beam lithography. This QD-placement technique resulted in an average of three QDs in each cluster, and 87% of the templated sites were occupied by at least one QD. These QD clusters could be in close proximity to one another, with a minimum separation of 12 nm. Photoluminescence measurements of the fabricated QD clusters showed intermittent photoluminescence, which indicates that the QDs were optically active after the fabrication process. This optimized top-down lithographic process is a step towards the integration of individual QDs in optoelectronic and nano-optical systems.
