Characterization of two-dimensional hexagonal boron nitride using scanning electron and scanning helium ion microscopy

Journal Article · Mon Jan 20 00:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4862819· OSTI ID:22280579

Guo, Hongxuan ^[1]; Gao, Jianhua; Ishida, Nobuyuki ^[2]; Xu, Mingsheng ^[3]; Fujita, Daisuke ^[4]

---

1. Global Research Center for Environment and Energy Based on Nanomaterials Science National Institute for Materials Science (NIMS) 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)
2. International Center for Young Scientists, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)
3. State Key Laboratory of Silicon Materials, Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China)
4. Advanced Key Technologies Division, Global Research Center for Environment and Energy Based on Nanomaterials Science, and International Center for Young Scientists, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

Characterization of the structural and physical properties of two-dimensional (2D) materials, such as layer number and inelastic mean free path measurements, is very important to optimize their synthesis and application. In this study, we characterize the layer number and morphology of hexagonal boron nitride (h-BN) nanosheets on a metallic substrate using field emission scanning electron microscopy (FE-SEM) and scanning helium ion microscopy (HIM). Using scanning beams of various energies, we could analyze the dependence of the intensities of secondary electrons on the thickness of the h-BN nanosheets. Based on the interaction between the scanning particles (electrons and helium ions) and h-BN nanosheets, we deduced an exponential relationship between the intensities of secondary electrons and number of layers of h-BN. With the attenuation factor of the exponential formula, we calculate the inelastic mean free path of electrons and helium ions in the h-BN nanosheets. Our results show that HIM is more sensitive and consistent than FE-SEM for characterizing the number of layers and morphology of 2D materials.

• OSTI ID: 22280579
• Journal Information: Applied Physics Letters, Vol. 104, Issue 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
BORON NITRIDES
FIELD EMISSION
HELIUM IONS
HEXAGONAL LATTICES
ION MICROSCOPY
LAYERS
MEAN FREE PATH
MORPHOLOGY
NANOSTRUCTURES
SCANNING ELECTRON MICROSCOPY
SHEETS
SUBSTRATES
SYNTHESIS
TWO-DIMENSIONAL CALCULATIONS