Abstract
We study the temperature dependence (77–475 K) of the longitudinal resistivity and Hall coefficient of thin films (thickness 20 nm) of three-dimensional topological Dirac semimetal grown via molecular beam epitaxy. The temperature-dependent Hall coefficient is electronlike at low temperature, but transitions to holelike transport around 200 K. We develop a model of a Dirac band with electron-hole asymmetry in Fermi velocity and mobility (assumed proportional to the square of Fermi velocity) which explains well the magnitude and temperature dependence of the Hall resistivity. We find that the hole mobility is about seven times larger than the electron mobility. In addition, we find that the electron mobility decreases significantly with increasing temperature, suggesting electron-phonon scattering strongly limits the room-temperature mobility.
- Received 4 September 2017
DOI:https://doi.org/10.1103/PhysRevB.96.235412
©2017 American Physical Society