Haibo Zeng^*, Yoshio Bando, Dmitri Golberg

International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan

^*zeng.haibo.nano@gmail.com

Abstract:

Hexagonal BN has similar structure to graphite, so called white graphite, but has completely different properties, such as insulating, higher thermal and chemical stability, band gap, and high thermal conductivity. Therefore, inspired by graphene, many groups have been attracted to fabricate two dimensional crystals of BN and to explore their novel properties. Currently, the fabrication of atomically thin sheets and ribbons is still a challenge for BN. But, mass of theoretical calculations have been published, promising very exciting potentials in optoelectronics and spintronics devices although the experimental evidences are still missing.

Herein, we report fabrication of atomically thin BN nanoribbons, analogues of graphene nanoribbons, and their electronics properties. The fabrication method involves the nanotube unzipping through plasma etching, wherein the layer number of BN nanoribbons can approach to single-layer through the modulation of plasma power and etching time, as shown in Figure 1. The microstructure characterizations demonstrated that the BN nanoribbons by this method prefer to be of zigzagged edges. Usually, BN is an insulator. This greatly depresses the application of BN nanostructures, such as previous BN nanotubes. Here, through electron transport investigation, the electronic conductivity of nanoribbons was found to be greatly improved with the formation of atomically thin ribbons, as shown in Figure 2. Through atomic imaging on the microstructure and theoretical calculation, we suggested that such conductivity improvement is induced by the zigzag edge states and vacancy defects. They act as shallow acceptor-like dopants.

This study could pave the way for the fabrication of inorganic graphene-like nanoribbons and their usages as functional semiconductors with a wide range of applications in optoelectronics and spintronics.

References:

[1]       H. B. Zeng, C. Y. Zhi, Z. H. Zhang, X. L. Wei, X. B. Wang, W. L. Guo, Y. Bando, D. Golberg, “White Graphenes”: Boron Nitride Nanoribbons via Boron Nitride Nanotube Unwrapping, Nano. Lett. 2010, 10, 5049-5055.

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