Related papers: Electronic Structure, Surface Doping, and Optical …
In atomically thin transition metal dichalcogenide semiconductors, there is a crossover from indirect to direct bandgap as the thickness drops to one monolayer, which comes with a fast increase of the photoluminescence signal. Here, we show…
Alloying enables engineering of the electronic structure of semiconductors for optoelectronic applications. Due to their similar lattice parameters, the two-dimensional semiconducting transition metal dichalcogenides of the MoWSeS group…
The search for a two-dimensional material that simultaneously fulfills some properties for its use in spintronics and optoelectronics, i.e., a suitable bandgap with high in-plane carrier mobility and good environmental stability, is the…
Ultrathin films of topological Dirac semimetal, Na$_3$Bi, has recently been revealed as an unusual electronic materials with field-tunable topological phases. Here we investigate the electronic and transport properties of ultrathin Na$_3$Bi…
Quantum systems in confined geometries are host to novel physical phenomena. Examples include quantum Hall systems in semiconductors and Dirac electrons in graphene. Interest in such systems has also been intensified by the recent discovery…
The electronic structure of epitaxial single-layer MoS$_2$ on Au(111) is investigated by angle-resolved photoemission spectroscopy. Pristine and potassium-doped layers are studied in order to gain access to the conduction band. The…
We report on fabrication of a two-dimensional topological insulator-Bi(111) bilayer on Sb nanofilms via a sequential molecular beam epitaxy (MBE) growth technique. Our angle-resolved photoemission measurements demonstrate the evolution of…
Vertical and lateral heterostructures of van der Waals materials provide tremendous flexibility for band structure engineering. Since electronic bands are sensitively affected by defects, strain, and interlayer coupling, the edge and…
Despite the weak nature of interlayer forces in transition metal dichalcogenide (TMD) materials, their properties are highly dependent on the number of layers in the few-layer two-dimensional (2D) limit. Here, we present a combined scanning…
The AB-stacked bilayer graphene (BLG) is a pure semiconductor whose band gap and properties can be tuned by various methods such as doping or applying gate voltage. Here we show an alternative method to control the electronic properties of…
Weyl Semimetals (WSMs), a recently discovered topological state of matter, exhibit an electronic structure governed by linear band dispersions and degeneracy (Weyl) points leading to rich physical phenomena, which are yet to be exploited in…
Two-dimensional (2D) materials have recently been the focus of extensive research. By following a similar trend as graphene, other 2D materials including transition metal dichalcogenides (MX2) and metal mono-chalcogenides (MX) show great…
The electronic band gap of a two-dimensional semiconductor within a device architecture is sensitive to variations in screening properties of adjacent materials in the device and to gate-controlled doping. Here, we employ micro-focused…
We present the electronic and structural properties of monolayer WSe$_{2}$ grown by pulsed-laser deposition on monolayer graphene (MLG) on SiC. The spin splitting in the WSe$_{2}$ valence band at $\overline{\mathrm{K}}$ was…
Among very low disorder systems of condensed matter, the high mobility two-dimensional electron gas confined in gallium arsenide/aluminum gallium arsenide heterostructures holds a privileged position as platform for the discovery of new…
We report the structural and optical properties of molecular beam epitaxy (MBE) grown 2-dimensional (2D) material molybdenum diselenide (MoSe2) on graphite, CaF2 and epitaxial graphene. Extensive characterizations reveal that 2H- MoSe2…
Two-dimensional (2D) elemental semiconductors have great potential for device applications, but their performance is limited by the lack of efficient doping methods. Here, combining molecular beam epitaxy, scanning tunneling…
Rhombohedral-stacked transition metal dichalcogenides (TMDs) break inversion symmetry between adjacent layers, giving rise to an intrinsic out-of-plane ferroelectric polarization.Controlling the formation of this stacking polytype is…
Two-dimensional lateral heterojunctions are basic components for low-power and flexible optoelectronics. In contrast to monolayers, devices based on few-layer lateral heterostructures could offer superior performance due to their lower…
Using angle-resolved photoemission spectroscopy (ARPES), we studied bulk and surface electronic band structures of narrow-gap semiconductor lead telluride (PbTe) thin films grown by molecular beam epitaxy both perpendicular and parallel to…