Observation of Low-Frequency Interlayer Breathing Modes in Few-Layer Black Phosphorus
As a new two-dimensional layered material, black phosphorus (BP) is a very promising material for nanoelectronics and optoelectronics. We use Raman spectroscopy and first-principles theory to characterize and understand the low-frequency (LF) interlayer breathing modes (<100 cm[superscript –1]) i...
Main Authors: | , , , , , , , , |
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Other Authors: | |
Format: | Article |
Language: | en_US |
Published: |
American Chemical Society (ACS)
2016
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Online Access: | http://hdl.handle.net/1721.1/100776 https://orcid.org/0000-0001-8492-2261 https://orcid.org/0000-0002-1955-3081 https://orcid.org/0000-0002-3618-9074 https://orcid.org/0000-0003-0551-1208 |
Summary: | As a new two-dimensional layered material, black phosphorus (BP) is a very promising material for nanoelectronics and optoelectronics. We use Raman spectroscopy and first-principles theory to characterize and understand the low-frequency (LF) interlayer breathing modes (<100 cm[superscript –1]) in few-layer BP for the first time. Using a laser polarization dependence study and group theory analysis, the breathing modes are assigned to A[subscript g] symmetry. Compared to the high-frequency (HF) Raman modes, the LF breathing modes are considerably more sensitive to interlayer coupling and, thus, their frequencies show a stronger dependence on the number of layers. Hence, they constitute an effective means to probe both the crystalline orientation and thickness of few-layer BP. Furthermore, the temperature dependence shows that in the temperature range −150 to 30 °C, the breathing modes have a weak anharmonic behavior, in contrast to the HF Raman modes that exhibit strong anharmonicity. |
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