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The applications of two-dimensional (2D) materials in electronics, optoelectronics, and spintronics are limited by the high contact resistance at the metal/semiconductor interface owing to the strong Fermi-level pinning. In this study, an interlayer insertion strategy is proposed to solve this problem, and first principles calculations are done to study the influences of inserting a SiC layer on the Schottky barrier and electronic properties of MoS2/metals (Mg, Al, In, Cu, Ag, Au, Pd, Ti, and Sc). The average charge value substantially increased (≥0.060 e) at the interface between SiC and MoS2 layers, and then no tunneling barrier appeared except for the MoS2/Au contact by inserting the SiC layer. Moreover, ΦSB,N almost decreases for the MoS2/metal contacts by inserting the SiC layer. When Ti, Cu, Au, and Pd are used as electrodes, the n-type Schottky barrier is formed with the ΦSB,N values of 0.479 eV, −0.073 eV, 0.498 eV, and 0.225 eV, respectively. However, if Al, In, Mg, and Ag are used as electrodes, the systems are transformed into Ohmic contact. These findings provide a practical guideline for depinning the Fermi level at contact interfaces and designing the high performance TMD-based nanoelectronic devices.

The quantum interference effect offers a unique route to control the charge transport through nanoscale constrictions. The carbon atomic chain, which is an sp-hybridized carbon allotrope, has recently stimulated interest to construct ultimate nano-devices. Instead of using the carbon atomic chain as an electron transmitting channel interconnecting nano-components, we explore the possibility of using side carbon chains to change the phase of the transmitting electrons and influence the interference pattern of the nano-device. Interference pattern modulation is a general phenomenon which is demonstrated in a benzene molecular device, a zigzag graphene nanoribbon device and a SiC nanoribbon device. Odd-even oscillation dependence of the conductance on the length of the side carbon chain is found. Two criteria, i.e. large magnitude of the local state in the side carbon chain and proper length of the side carbon chain, must be satisfied simultaneously to achieve effective interference modulation. By carefully choosing the position and length of the side carbon chains, the transmission zero can be moved to the Fermi energy. Moreover, the transmission zero induced by destructive interference at the Fermi energy can be very robust against strain. This work provides a new possibility to construct nano-devices with carbon atomic chains.

Within the framework of two-component pseudo-potentials, the coupled-cluster theory with spin-orbit interaction and the equation-of-motion coupled-cluster theory with spin-orbit interaction for ionized states are employed to obtain the spectroscopic constants of the ground-state Cu2, Ag2, and Au2 in this work. The spin-orbit interaction is only calculated iteratively in the post-Hartree-Fock, i.e. the coupled-cluster procedure. It is shown that the CCSD(T) approach with spin-orbit interaction is capable of providing the rather accurate equilibrium distances and harmonic frequencies. Furthermore, the equation-of-motion coupled-cluster approach with spin-orbit interaction for ionized states is able to reasonably estimate the spin-orbit contribution to the binding energy. Hence, the accurate binding energies are obtained by the scalar-relativistic CCSD(T) calculations with the correction of spin-orbit contribution. In addition, the spectroscopic constants have a weak basis set dependence for all the title species.

The flexibility and quasi-one-dimensional nature of nanowires offer wide-ranging possibilities for novel heterostructure design and strain engineering. In this work, we realized controllably bent Si nanowires by using asymmetric growth with electron beam evaporation system. It is demonstrated that the degree of arc-bending depends on the deposition angle and deposition thickness. The forward bending of the Si nanowires is due to the lattice mismatch and thermal mismatch between Si and the metallic materials such as Cr and Ti, which can be generally utilized to control the shape and internal strain of Si nanowires, with potential applications for fabricating desired nano-devices.

Understanding the interfacial properties between two-dimensional (2D) semiconductors and metal electrodes is vital for designing and realization of electronic devices. In this paper, first-principle calculations are done to study the influences of the defects on the interfacial electronic states of mMoS2/metal (metal= Mg, Al, In, Cu, Ag, Au, and Pd). It is found that the electron states at the interface are substantially increased if defects are induced in mMoS2 contacted with metals. As a result, the tunneling barrier is reduced. The Schottky barrier height (SBH) is increased in mMoS2 contacted with Mg, Al, In, and Au, but is reduced in defective mMoS2 contacted with Cu, Ag, and Pd. Furthermore, the pinning factor S are 0.227, 0.238, and 0.238 for the VS, VMo, and SMo in mMoS2, but the S value is only 0.030 for substitution of S by Mo (MoS) in mMoS2. Our findings are in good agreement with the experimental results. The results give insight into the contact physics of 2D semiconductors with metals and it is suggested that defects play a key role on the future generation electronic applications.

The CCSD(T) approach based on two-component relativistic effective core potential with spin–orbit interaction just included in coupled cluster iteration is adopted to study the spectroscopic constants of ground states of Kr 2 , Xe 2 and Rn 2 dimers. The spectroscopic constants have significant basis set dependence. Extrapolation to the complete basis set limit provides the most accurate values. The spin–orbit interaction hardly affects the spectroscopic constants of Kr 2 and Xe 2 . However, the equilibrium bond length is shortened about 0.013 A and the dissociation energy is augmented about 18 cm −1 by the spin–orbit interaction for Rn 2 in the complete basis set limit.

In order to realize a flexible visible-near-infrared (VIS-NIR) photodetector, Si nanowires (SiNWs) were prepared on graphene (Gr) by using metal-catalyzed chemical vapor deposition, and then the Gr/SiNWs heterojunction was transferred onto a flexible polytetrafluoroethylene (PTFE) substrate by using a polymethylmethacrylate (PMMA)/polydimethylsiloxane (PDMS) as a double-layer support film. The transfer process of the flexible Gr/SiNWs heterojunction was successful. However, the mechanical stress induced by the spin coating process and volume shrinkage of the PMMA/PDMS layers had an impact on the crystalline structure of the SiNWs. The as-fabricated Gr/SiNWs heterojunction photodiode indicated rectifying behavior. Under VIS-NIR illumination of 0.1 W/cm2, an apparent operation of the photodiode with a photoelectric effect was observed.

Zigzag graphene nanoribbons (ZGNRs) are expected to serve as the promising component in the all-carbon spintronic device. It remains challenging to fabricate a device based on ZGNRs with high spin-filter efficiency and low experimental complexity. Using density functional theory combined with nonequilibrium Green’s function technique, we studied the spin-dependent transport properties of the tailored zigzag graphene nanoribbon. A perfect spin-filtering effect is found in the tailored structure of ZGNR. The nearly 100% spin-polarized current and high magneto-resistance ratio can be obtained by applying a homogeneous magnetic field across the device. The distribution of spin up and spin down states at the bridge carbon atom plays a dominant role in the perfect spin filtering. The tailoring of ZGNR provides a new effective approach to graphene-based spintronics.