Chemically detaching hBN crystals grown at atmospheric pressure and high temperature for high-performance graphene devices

Abstract

In this work, we report on the growth of hexagonal boron nitride (hBN) crystals from an iron flux at atmospheric pressure and high temperature and demonstrate that (i) the entire sheet of hBN crystals can be detached from the metal in a single step using hydrochloric acid and that (ii) these hBN crystals allow the fabrication of high carrier mobility graphene devices. By combining spatially-resolved confocal Raman spectroscopy and electrical transport measurements, we confirm the excellent quality of these crystals for high-performance hBN-graphene-based van der Waals heterostructures. The full width at half maximum of the graphene Raman 2D peak is as low as 16 cm${}^{-1}$, and the room temperature charge carrier mobilitiy is around 80000 cm${}^2$/(Vs) at a carrier density 1$\times$10${}^{12}$cm${}^{-12}$. This is fully comparable with devices of similar dimensions fabricated using crystalline hBN synthesized by the high pressure and high temperature method. Finally, we show that for exfoliated high-quality hBN flakes with a thickness between 20 nm and 40 nm the line width of the hBN Raman peak, in contrast to the graphene 2D line width, is not useful for benchmarking hBN in high mobility graphene devices.

7 pages, 4 figures

References in corpus (8)

• 2D materials and van der Waals heterostructures
• Boron nitride substrates for high-quality graphene electronics
• Magnetic 2D materials and heterostructures
• Transport spectroscopy of ultraclean tunable band gaps in bilayer graphene
• Unveiling valley lifetimes of free charge carriers in monolayer WSe${}_2$
• Excellent electronic transport in heterostructures of graphene and monoisotopic boron-nitride grown at atmospheric pressure
• An open-source robust machine learning platform for real-time detection and classification of 2D material flakes
• Charge carrier density-dependent Raman spectra of graphene encapsulated in hexagonal boron nitride

Cited by in corpus (6)

• An open-source robust machine learning platform for real-time detection and classification of 2D material flakes
• Benchmarking the integration of hexagonal boron nitride crystals and thin films into graphene-based van der Waals heterostructures
• Electrically Controlled Interfacial Charge Transfer Induced Excitons in MoSe2-WSe2 Lateral Heterostructure
• Current-induced brightening of vacancy-related emitters in hexagonal boron nitride
• Hexagonal boron nitride crystal growth in the Li3BN2-BN system
• Electronic and Spin-Orbit Properties of hBN Encapsulated Bilayer Graphene