Single Quantum Emitters Based on Strained Quantum Dots in Two-Dimensional Semiconductors
Abstract
Quantum confinement in atomically-thin transition-metal dichalcogenides (TMDs) has been explored recently for single quantum emitters based on naturally occurring or artificially created defects. In this project, PIs Nam and Park aim to advance our understanding of artificial quantum emitters of atomically-thin TMDs on their emission properties by investigating the effect of deterministic straining and confinement, as opposed to unintentional defects. We propose that mechanical straining and confinement in monolayer TMDs are viable solutions to produce precisely controlled single quantum emitters. In our system, localized (or confined) excitons arise from a confinement potential caused by a local strain gradient. In addition, the two-dimensional (2D) nature of a single quantum emitter confined to an atomically-thin material can greatly enhance the photon-extraction efficiency. Our collaborative team has demonstrated that heterogeneous straining of 2D TMDs (with a localized strain level of 0-4 percent) can induce efficient exciton funneling across microns at room temperature. Moreover, we showed that localized deformation of 2D TMDs on nanogap can lead to single photon emission with deterministic position and polarization. With the support of AOARD and IITP, PIs Nam and Park published a total of 20 papers in high impact journals, including Nature Electronics, Advanced Materials, Materials Today, etc. We also published two collaborative papers (1) polarization-controlled single photon emission of strained WSe2 in Nano Letters and (2) crumpled graphene induced plasmon resonance in Light: Science and Applications. We predict that as the scale of deformation approaches that of exciton Bohr radius, the strained and confined 2D excitons will result in an efficient, single-photon source based on strained 2D semiconductors for next generation, scalable quantum cryptography.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 12, 2023
- Accession Number
- AD1226619
Entities
People
- Hong-Gyu Park
- SungWoo Nam
Organizations
- Korea University
- University of Illinois Urbana–Champaign