Fermi Level

Surface-enhanced Raman scattering (SERS) is a powerful fingerprint analysis and detection technique that plays an important role in the fields of food safety, environmental protection, bio-imaging and hazardous substance identification. Electromagnetic enhancement (EM) and chemical enhancement (CM) are the two recognized mechanisms of action for amplifying Raman signals.

A Chinese team has published new work on battery designs employing heterostructured nanoflowers in Energy Material Advances.

A paper published on Dec. 21 in Energy Material Advances reviews improvement strategies for the electrocatalytic activities of transition metal nitrides (TMNs) on hydrogen evolution reaction.

Exploring novel topological materials and related phase transitions has been a central research theme in condensed matter physics and materials science. Topological materials with nontrivial anti-band crossings have attracted much attention. Hourglass fermion surface state, located at the vertex in the neck of an hourglass-like dispersion, enables exploration of remarkable topological phases, such as the hourglass…

The stability of graphene-based field-effect transistors with amorphous aluminium oxide serving as the top-gate oxide can be improved by tuning the Fermilevel of the two-dimensional channel material such that it maximizes the energy distance between the charge carriers in the channel and the defect bands in the gate oxide.

Conventional silicon-based transistors, which sit at the heart of every computer, are fast approaching the limit of miniaturisation. Here, Meng et al demonstrate a field-effect transistor composed of a single rutheniumdiarylethene molecule with large on/off ratio.

Superconductivity refers to the loss of electrical resistance of a material and requires extremely low temperatures (< -200 degrees Celsius) in order to persist. This low temperature, otherwise known as the transition temperature, has been a limiting factor in the application of superconductors and finding materials that can display superconductivity at higher temperatures has become an important research objective…

An MIT-led group has learned how to achieve precise control over the properties of Weyl semimetals and other exotic substances. The technique can be used any inorganic bulk material and for thin films.

In 1911, Heike Kamerlingh Onnes discovered the first superconductor, metallic mercury when cooled to a critical temperature of 4.2 Kelvin, where it conducts electricity without resistance. Ever since materials scientists have been on a quest to better understand the phenomenon and whether other elements and materials have higher critical temperatures that could make them useful for practical electricity transport,…

A spin-triplet pair density wave is discovered in the candidate topological superconductor UTe2 using superconductive scanning tunnelling microscopy tips.

Scientists from Tokyo Metropolitan University have successfully engineered multi-layered nanostructures of transition metal dichalcogenides that meet in-plane to form junctions. They grew out layers of multi-layered structures of molybdenum disulfide from the edge of niobium doped molybdenum disulfide shards, creating a thick, bonded, planar heterostructure. They demonstrated that these may be used to make new…

Weyl semimetals are topological materials whose low-energy excitations obey the Weyl equation. In a Weyl semimetal, the conduction and valence bands touch at discrete points in momentum space called Weyl nodes. Weyl nodes are monopoles of the Berry curvature and are robust under generic perturbations. The quasiparticles near the Weyl nodes are analogous to Weyl fermions in high-energy physics; they exhibit linear…

Developing low-cost and stable metal electrodes is crucial for mass production of perovskite solar cells (PSCs). As an earth-abundant element, Cu becomes an alternative candidate to replace noble metal electrodes such as Au and Ag, due to its comparable physiochemical properties with simultaneously good stability and low cost. However, the undesirable band alignment associated with the device architecture impedes…

Pt-based catalysts have been extensively employed in catalytic propane dehydrogenation (PDH) processes, playing a crucial role in propylene production. However, monometallic Pt catalysts often exhibit inferior propylene selectivity due to the hydrogenolysis, rapid deactivation from coke deposits, and nanoparticle sintering. To address these challenges, various metals (Sn, Zn, Ga, Co, etc.) have been introduced to…

Two recent preprints in physics archive (arXiv) have called the attention as they claim experimental evidence that a Cu-substituted apatite material (called LK-99) exhibits superconductivity at room temperature and pressure. If this proves to be true, LK-99 will be the holy grail of superconductors. In this work, we used Density-Functional Theory calculations to elucidate some key features of the electronic…

Quantum advances rely on the production of nanoscale wires that are based on several state-of-the-art nanolithographic technologies, to develop wires via bottom-up synthesis. However, a critical challenge is to grow uniform atomic crystalline wires and construct network structures to build nanocircuits.

Northeastern researchers have made what they describe as a groundbreaking discovery in the field of quantum mechanics.

Quantum magnets can be studied using high-resolution spectroscopic studies to access magnetodynamic quantities including energy barriers, magnetic interactions, and lifetime of excited states. In a new report now published in Science Advances, Sascha Brinker and a team of scientists in advanced simulation and microstructure physics in Germany studied a previously unexplored flavor of low-energy spin excitation for…

The layered vanadium antimonides AV3Sb5 (A = K, Rb, Cs) are a recently discovered family of topological kagome metals with a rich phenomenology of strongly correlated electronic phases including charge order and superconductivity. Understanding how the singularities inherent to the kagome electronic structure are linked to the observed many-body phases is a topic of great interest and relevance. Here, we combine…

The photoelectrochemical (PEC) overall water-splitting reaction (OWS) has been fully developed in the past decade, especially in new catalysts, characterization methods and reaction mechanisms. Compared with the hydrogen evolution reaction (HER), the oxygen evolution reaction (OER) is deemed the bottleneck of OWS due to its sluggish kinetics.