Deterministic generation and tuning of single photon emitters in 2d materials

Abstract

The central goal of this thesis is to establish a deterministic method for generating and tuning single photon emission in two-dimensional (2D) materials through strain engineering and controlled coupling to plasmonic nanostructures. By integrating strain-induced defect formation with tailored plasmonic architecture, this work demonstrates a pathway for selective radiative rate enhancement, enabling robust control over emitter-antenna interactions relevant to applications in quantum photonics, biosensing, and nanoscale optoelectronics. The first part of this thesis focuses on tungsten diselenide (WSe2), as a strain-tunable quantum emitter platform at cryogenic temperatures. WSe2 films synthesized via metal organic chemical vapor deposition (MOCVD) and flowable chemical vapor deposition (CVD) are optically characterized prior to integration with hybrid strain-plasmonic platforms. To create a tunable electromagnetic environment, plasmonic bowtie nanoantenna with systematically varied geometries are designed and fabricated, with simulations and spectroscopy revealing how geometric parameters govern field confinement and resonance energies. Building on these insights, a two-step strain engineering strategy is developed to reproducibly generate emitters at predetermined locations. Deterministic placement of these strain-induced emitters into the near field of individual bowtie antennas is then demonstrated, with photoluminescence mapping and photon correlation measurements confirming selective activation and enhanced radiative emission relative to uncoupled controls. In a complementary effort, this thesis investigates hexagonal boron nitride (h-BN) as a wide-bandgap host for defect-based single-photon emission at room temperature. The intrinsic optical and structural properties of h-BN are introduced, followed by the synthesis of h-BN thin films with and without plasmonic nanoparticles using a liquid-liquid interface assembly method. By examining the emission properties of both film types, this work demonstrates the tunability of defect photoluminescence and a measurable reduction in lifetime for nanoparticle-containing films, indicating enhanced radiative channels facilitated by plasmonic coupling. Collectively, this work develops a reproducible platform for generating, positioning, and tuning solid-state quantum emitters in 2D materials using plasmonic nanoparticles. The fabrication strategies and optical studies presented here lay the groundwork for future explorations of hybrid quantum-plasmonic systems both experimentally and computationally.