We report the discovery of two-dimensional electron gas (2DEG) at the surface of thermoelectric material In4Se3 by angle-resolved photoemission spectroscopy. The observed 2DEG exhibits a nearly isotropic band dispersion with a considerably small effective mass of m∗=0.16 m0, and its carrier density shows a significant temperature dependence, leading to unconventional metal-semiconductor transition at the surface. The observed wide-range thermal tunability of 2DEG in In4Se3 gives rise to additional degrees of freedom to better control the surface carriers of semiconductors.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics