Fabrication of Atomically Precise Nanopores in Hexagonal Boron Nitride

TL;DR

This paper presents a method for fabricating atomically precise nanopores in hexagonal boron nitride using electron beam irradiation, enabling controlled pore size and edge chemistry for various applications.

Contribution

It introduces a novel technique for creating precisely controlled nanopores in hBN with specific edge terminations, improving upon irregular pore fabrication methods.

Findings

Achieved controlled growth of nanopores from subnanometer to 6nm in diameter.

Demonstrated selective edge termination of nanopores with nitrogen or boron.

Enabled large-area fabrication of uniform nanopores with atomic precision.

Abstract

We demonstrate the fabrication of individual nanopores in hexagonal boron nitride (hBN) with atomically precise control of the pore size. Previous methods of pore production in other 2D materials create pores of irregular geometry with imprecise diameters. By taking advantage of the preferential growth of boron vacancies in hBN under electron beam irradiation, we are able to observe the pore growth via transmission electron microscopy, and terminate the process when the pore has reached its desired size. Careful control of beam conditions allows us to nucleate and grow individual triangular and hexagonal pores with diameters ranging from subnanometer to 6nm over a large area of suspended hBN using a conventional TEM. These nanopores could find application in molecular sensing, DNA sequencing, water desalination, and molecular separation. Furthermore, the chemical edge-groups along the hBN pores can be made entirely nitrogen terminated or faceted with boron-terminated edges, opening avenues for tailored functionalization and extending the applications of these hBN nanopores.