Related papers: Electroluminescence from indirect band gap semicon…
We report the realization of field-effect transistors (FETs) made with chemically synthesized multilayer 2D crystal semiconductor MoS2. Electrical properties such as the FET mobility, subthreshold swing, on/off ratio, and contact resistance…
The integration of two-dimensional materials such as transition metal dichalcogenides with bulk semiconductors offer interesting opportunities for 2D/3D heterojunction-based novel device structures without any constraints of lattice…
We investigate the effects of environmental dielectric screening on the electronic dispersion and the band gap in the atomically-thin, quasi two-dimensional (2D) semiconductor WS$_2$ using correlative angle-resolved photoemission and…
Using first-principles calculations we show that the band gap of bilayer sheets of semiconducting transition metal dichalcogenides (TMDs) can be reduced smoothly by applying vertical compressive pressure. These materials undergo a universal…
We perform an in-plane optical spectroscopy measurement on high quality FeSe single crystals grown by a vapor transport technique. Below the structural transition at $T_{\rm s}\sim$90 K, the reflectivity spectrum clearly shows a gradual…
Inspired by the recent first-principles calculations showing the high thermoelectric performance of layered pnictogen chalcogenides, we experimentally characterise the crystal structure and high-temperature transport properties of the…
Conventional metals, in general, do not exhibit strong photoluminescence. 2H-TaSe$_2$ is a layered transition metal dichalcogenide that possesses metallic property with charge density wave characteristics. Here we show that 2H-TaSe$_2$…
Two-dimensional (2D) transition metal dichalcogenides (TMDs) based photodetectors have shown great potential for the next generation optoelectronics. However, most of the reported MoS2 photodetectors function under the photogating effect…
Semiconductor heterostructures are the fundamental platform for many important device applications such as lasers, light-emitting diodes, solar cells and high-electron-mobility transistors. Analogous to traditional heterostructures, layered…
Developing novel techniques for depositing transition metal dichalcogenides is crucial for the industrial adoption of 2D materials in optoelectronics. In this work, the lateral growth of molybdenum disulfide (MoS2) over an insulating…
Electronic structure of newly synthesized single crystals of calcium iron arsenide doped with sodium with Tc ranging from 33 to 14 K has been determined by angle-resolved photoemission spectroscopy (ARPES). The measured band dispersion is…
Field-effect transistors (FETs) with non-covalently functionalised molybdenum disulfide (MoS2) channels grown by chemical vapour deposition (CVD) on SiO2 are reported. The dangling-bond-free surface of MoS2 was functionalised with a…
Ferroelectric field-effect transistors (FeFET) with two-dimensional (2D) semiconductor channels are promising low-power, embedded non-volatile memory (NVM) candidates for next-generation in-memory computing. However, the performance of…
Applying elastic deformation can tune a material physical properties locally and reversibly. Spatially modulated lattice deformation can create a bandgap gradient, favouring photo-generated charge separation and collection in optoelectronic…
The band gaps of isostructural Bi2OS2 and LaOBiS2 were examined using optical absorption and discussed with the band structures calculated based on the crystal structures determined using synchrotron X-ray diffraction. The Bi 6p and S 3p…
Two-dimensional crystals, single sheets of layered materials, often show distinct properties desired for optoelectronic applications, such as larger and direct band gaps, valley- and spinorbit effects. Being atomically thin, the low amount…
We report a strain-induced direct-to-indirect band gap transition in mechanically deformed WS2 monolayers (MLs). The necessary amount of strain is attained by proton irradiation of bulk WS2 and the ensuing formation of one-ML-thick,…
Transition-metal dichalcogenides (TMDCs) are important class of two-dimensional (2D) layered materials for electronic and optoelectronic applications, due to their ultimate body thickness, sizable and tunable bandgap, and decent theoretical…
Properties of layered superconductors can vary drastically when thinned down from bulk to monolayer, owing to the reduced dimensionality and weakened interlayer coupling. In transition metal dichalcogenides (TMDs), the inherent symmetry…
Band gap anomaly is a well-known issue in lead chalcogenides PbX (X=S, Se, Te, Po). Combining ab initio calculations and tight-binding (TB) method, we have studied the band evolution in PbX, and found that the band gap anomaly in PbTe is…