Correlated Structural and Optical Characterization of Hexagonal Boron Nitride

Area of Science:

• Materials Science
• Condensed Matter Physics
• Quantum Optics

Background:

• Hexagonal boron nitride (hBN) is crucial for nanoelectronics and nanophotonics.
• hBN exhibits room-temperature quantum emitters and optically addressable spins, vital for quantum technologies.
• The influence of surface contamination on hBN's properties is largely unexplored.

Purpose of the Study:

• To investigate the correlation between surface residue, flake morphology, and optical emission in hBN.
• To understand how microscopy techniques and common treatments affect hBN's optical and structural characteristics.
• To highlight the necessity of correlative studies for characterizing two-dimensional materials.

Main Methods:

• Preparation of hBN samples suitable for confocal photoluminescence (PL) microscopy, transmission electron microscopy (TEM), and atomic-force microscopy (AFM).
• Quantitative analysis of fluorescent emission, flake morphology, and surface residue using correlative microscopy.
• Evaluation of the effects of annealing and oxygen plasma cleaning on hBN structure and optical activity.

Main Results:

• Microscopy techniques induce changes: PL causes photobleaching, and TEM alters surface residue and emission.
• Surface contamination and residue morphology are directly linked to hBN's optical emission.
• Annealing and oxygen plasma treatments modify hBN's structure and optical properties.

Conclusions:

• Surface contamination and experimental conditions significantly influence hBN's optical and structural properties.
• Correlative microscopy is essential for accurately characterizing hBN and other 2D materials.
• Understanding these factors is key to optimizing hBN for quantum applications.