2D field-effect transistors (FETs) fabricated with transition metal dichalcogenide (TMD) materials are a potential replacement for the silicon-based CMOS. However, the lack of advancement in p-type contact is also a key factor hindering TMD-based CMOS applications. The less investigated path towards improving electrical characteristics based on contact geometries with low contact resistance (R_C) has also been established. Moreover, finding contact metals to reduce the R_C is indeed one of the significant challenges in achieving the above goal. Our research provides the first comparative analysis of the three contact configurations for a WSe₂ monolayer with different noble metals (Rh, Ru, and Pd) by employing ab initio density functional theory (DFT) and non-equilibrium Green’s function (NEGF) methods. From the perspective of the contact topologies, the R_C and minimum subthreshold slope (SS_MIN) of all the conventional edge contacts are outperformed by the novel non-van der Waals (vdW) sandwich contacts. These non-vdW sandwich contacts reveal that their R_C values are below 50 Ω∙μm, attributed to the narrow Schottky barrier widths (SBWs) and low Schottky barrier heights (SBHs). Not only are the R_C values dramatically reduced by such novel contacts, but the SS_MIN values are lower than 68 mV/dec. The new proposal offers the lowest R_C and SS_MIN, irrespective of the contact metals. Further considering the metal leads, the WSe₂/Rh FETs based on the non-vdW sandwich contacts show a meager R_C value of 33 Ω∙μm and an exceptional SS_MIN of 63 mV/dec. The two calculated results present the smallest-ever values reported in our study, indicating that the non-vdW sandwich contacts with Rh leads can attain the best-case scenario. In contrast, the symmetric convex edge contacts with Pd leads cause the worst-case degradation, yielding an R_C value of 213 Ω∙μm and an SS_MIN value of 95 mV/dec. While all the WSe₂/Ru FETs exhibit medium performances, the minimal shift in the transfer curves is interestingly advantageous to the circuit operation. Conclusively, the low-R_C performances and the desirable SS_MIN values are a combination of the contact geometries and metal leads. This innovation, achieved through noble metal leads in conjunction with the novel contact configurations, paves the way for a TMD-based CMOS with ultra-low R_C and rapid switching speeds.

The social distancing reinforcement under COVID-19 seriously limited the opportunities of practising and performing for arts and music performers. While many activities can be transferred online with minimal effort, the latency obstacle in using live streaming audio software negatively affects the musicians and singers in performing or practising online. The researchers sought to integrate both asynchronous and synchronous solutions to mitigate the demand of rehearsal practices. This action research applied and examined the viability of both low audio latency technology and mobile learning applications with amateur choir members. The researchers and participants field-tested and improved the choir’s online practice by using the JackTrip Audio Device (an audio low-latency device), Sight Singing Studio and Practice Bird (two mobile apps). Using current technology, we found that amateur choir singers have opportunities to keep learning and performing ‘together’ while staying healthy from virus threats.

This letter represents the first direct experimental demonstrations and mechanism proposal regarding abnormal palladium diffusion into germanium (Ge). Our experiments indicated that excess Ge atoms among palladium germanide alloy formation indirectly induce the abnormal out-diffusion of mass palladium atoms into Ge. Consequently, palladium germanide alloy on both n-type and p-type Ge form ohmic-like Schottky junctions. To identify this phenomenon, first-principle calculations and technology computer-aided design simulation were used to evaluate the electrical influence of palladium atoms in Ge. We discovered that the activated palladium atoms in Ge induce large midgap bulk-trap states, which contribute to a severe increment of trap-assisted tunneling current at the palladium germanide/Ge junction.

The unexpected properties of a uniaxially expanded TiN bulk arising from increasing the layer spacing from equilibrium are explored using a first-principles approach. We reveal an unusual nonmagnetic-magnetic transition from a TiN bulk to its monolayer. We also investigate the electronic and magnetic structures of a few TiN atomic layers. We find that the bilayer and trilayer, like the TiN bulk, are nonmagnetic poor metals. On the other hand, the monolayer TiN is found to carry a magnetic moment on its Ti atoms, and likely be a semiconductor. The unpaired electron giving rise to magnetism on Ti is primarily in the orbital perpendicular to the layers, and we find it is freed to give rise to magnetism when the layers are slightly separated. We find two different antiferromagnetic states possible on the monolayer, as well as one ferromagnetic, with one of the antiferromagnetic being the lowest energy. The exchange couplings between Ti atoms in such a monolayer are calculated to be antiferromagnetic for both the nearest-neighbor and next-nearest-neighbor sites. We also analyze the binding nature of both the monolayer and bilayer TiN by examining the predominant binding orbitals.

Two‐dimensional semiconductors are promising channel materials for next‐generation electronics because of their atomic thickness and strong electrostatic control. Among them, monolayer WSe ₂ is particularly attractive for complementary logic owing to its balanced electron and hole transport. However, realizing high‐performance homo‐channel CMOS remains limited by insufficient polarity control, Fermi‐level pinning, and contact resistance. Here, a complementary polarity‐engineering strategy is demonstrated in monolayer WSe ₂ using AlN and MoO _x . AlN induces n‐type modulation through interfacial/electrostatic effects, whereas MoO _x enables p‐type behavior through high‐work‐function charge transfer. The doping strength is tuned by deposition conditions and post‐annealing, enabling systematic threshold‐voltage control. As a result, AlN‐modulated n‐FETs exhibit a 2–3 orders of magnitude enhancement in current density and low contact resistance of ∼1 kΩ·µm, while MoO _x ‐modulated p‐FETs achieve current densities above 400 µA/µm. By integrating both polarities on a single WSe ₂ channel, homo‐channel CMOS inverters exhibit near‐ideal switching points (V _M ≈ V _DD /2), high noise margins(∼80%–90% of V _DD ), and low static power consumption of ∼0.1–10 pW. This work provides a route toward energy‐efficient 2D CMOS platforms.

Realizing n- and p-type transition metal dichalcogenide (TMD)-based field-effect transistors for nanoscale complementary metal oxide semiconductor (CMOS) applications remains challenging owing to undesirable contact resistance. Quantumtransport calculations were performed by replacing single-sided Se atoms of TMD near the interface with As or Br atoms to further improve the contact resistance. Here, partial selenium replacement produced a novel interface with a segment of metamaterial MoSeX (Pt/MoSeX/MoSe₂; X = As, Br). Such stable metamaterials exhibit semi-metallicity, and the contact resistance can be thus lowered. Our findings provide insights into the potential of MoSe₂-based nano-CMOS logic devices.