Deterministic Printing of Single Quantum Dots

TL;DR

This paper introduces SPEED printing, a deterministic, scalable, and sustainable nanomanufacturing method for precisely placing single quantum dots, advancing quantum photonic device fabrication.

Contribution

The paper presents a novel electrohydrodynamic printing technique that enables deterministic placement of single quantum dots with nanoscale precision, overcoming previous stochastic limitations.

Findings

Achieved selective extraction and deposition of individual QDs at sub-zeptoliter volumes.

Confirmed single-photon emission from printed QDs via photoluminescence and autocorrelation measurements.

Demonstrated scalable integration of quantum dots into photonic circuits.

Abstract

The unique optical properties of quantum dots (QDs), size-tunable emission and high quantum yield, make them ideal candidates for applications in secure quantum communication, quantum computing, targeted single-cell and molecular tagging, and sensing. Scalable and deterministic heterointegration strategies for single QDs have, however, remained largely out of reach due to inherent material incompatibilities with conventional semiconductor manufacturing processes. To advance scalable photonic quantum device architectures, it is therefore crucial to adopt placement and heterointegration strategies that can address these challenges. Here, we present an electrohydrodynamic (EHD) printing model, single particle extraction electrodynamics (SPEED) printing, that exploits a novel regime of nanoscale dielectrophoretics to print and deterministically position single colloidal QDs. Using QDs solubilized in apolar solvents, this additive, zero-waste nanomanufacturing process overcomes continuum fluid surface energetics and stochastic imprecision that limited previous colloidal deposition strategies, achieving selective extraction and deposition of individual QDs at sub-zeptoliter volumes. Photoluminescence and autocorrelation function (g(2)) measurements confirm nanophotonic cavity-QD integration and single-photon emission from single printed QDs. By enabling deterministic placement of single quantum dots, this method provides a powerful, scalable, and sustainable platform for integrating complex photonic circuits and quantum light sources with nanoscale precision.