High-Velocity Saturation in Graphene Encapsulated by Hexagonal Boron Nitride
| Autor: | David Goldhaber-Gordon, Wenmin Yang, Eric Pop, Megan Yamoah |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Drift velocity
Materials science Condensed matter physics Silicon Phonon scattering Carrier scattering Graphene General Engineering Analytical chemistry General Physics and Astronomy chemistry.chemical_element Saturation velocity 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences law.invention chemistry.chemical_compound chemistry law Boron nitride Electric field 0103 physical sciences General Materials Science 010306 general physics 0210 nano-technology |
| Zdroj: | ACS Nano. 11:9914-9919 |
| ISSN: | 1936-086X 1936-0851 |
| DOI: | 10.1021/acsnano.7b03878 |
| Popis: | We measure drift velocity in monolayer graphene encapsulated by hexagonal boron nitride (hBN), probing its dependence on carrier density and temperature. Due to the high mobility (>5 × 104 cm2/V/s) of our samples, the drift velocity begins to saturate at low electric fields (∼0.1 V/μm) at room temperature. Comparing results to a canonical drift velocity model, we extract room-temperature electron saturation velocities ranging from 6 × 107 cm/s at a low carrier density of 8 × 1011 cm–2 to 2.7 × 107 cm/s at a higher density of 4.4 × 1012 cm–2. Such drift velocities are much higher than those in silicon (∼107 cm/s) and in graphene on SiO2, likely due to reduced carrier scattering with surface optical phonons whose energy in hBN (>100 meV) is higher than that in other substrates. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|