Bottom-Up Synthesis of Hexagonal Boron Nitride Nanoparticles with Intensity-Stabilized Quantum Emitters

TL;DR

This paper presents a scalable bottom-up method to synthesize sub-10 nm hexagonal boron nitride nanoparticles with stable, bright quantum emitters, enhancing their photostability for nanoscale imaging and sensing.

Contribution

It introduces a catalyst-free hydrothermal synthesis process and a silica coating stabilization protocol for high-quality, photostable quantum emitters in hBN nanoparticles.

Findings

Achieved sub-10 nm hBN nanoparticles with bright emitters

Reduced intensity fluctuation by approximately 85%

Narrowed emission linewidth by about 14%

Abstract

Fluorescent nanoparticles are widely utilized in a large range of nanoscale imaging and sensing applications. While ultra-small nanoparticles (size <10 nm) are highly desirable, at this size range their photostability can be compromised due to effects such as intensity fluctuation and spectral diffusion caused by interaction with surface states. In this letter, we demonstrate a facile, bottom-up technique for the fabrication of sub-10-nm hBN nanoparticles hosting photostable bright emitters via a catalyst-free hydrothermal reaction between boric acid and melamine. We also implement a simple stabilization protocol that significantly reduces intensity fluctuation by ~85% and narrows the emission linewidth by ~14% by employing a common sol-gel silica coating process. Our study advances a promising strategy for the scalable, bottom-up synthesis of high-quality quantum emitters in hBN nanoparticles.