Metal doping induced tuning effects on geometry, electronic structure, carrier mobility, and device properties of armchair graphene nanoribbons are studied systematically and analyzed in detail.

Blue phosphorene (BlueP) has been widely researched recently as a potential material for novel photocatalytic and electronic devices. In this letter, due to its similar in-plane hexagonal lattice structure to MoS2, BlueP/MoS2 van der Waals heterostructures were built in six configurations. The II-stacking configuration was the most stable due to the lowest binding energy obtained from the calculation results. Furthermore, by controlling the external vertical strain, the geometry structures were optimized and the electronic structures of the BlueP/MoS2 heterostructure were modulated. We found that when the interlayer distance was 3.71 Å, the structure was the most optimized. In addition, as the result of charge transfer at the interlayer, a built-in electric field was formed in the BlueP/MoS2 heterostructure, which explained the formation of the type-II band alignment structure. The optical properties results show that the BlueP/MoS2 heterostructure has a wide optical response range and good light absorption ability, which indicated significant potential for BlueP/MoS2 heterostructure use in the next generation of photovoltaic devices and water-splitting materials.

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Recently, the arsenic monolayer has been successfully fabricated by micromechanical stripping. However, it is a non-magnetic semiconductor, including its derivatives. Here, we theoretically explore how to induce magnetism for arsenene armchair nanotubes (AsANTs) with a low-concentration TM (TM = Co, Y, Rh, Ni, Mo, Ru) atom doping, especially focusing on their structural stability, magneto-electronic property, carrier mobility, and strain effects. The high stability of these doped tubes are confirmed by the calculated binding energy and formation energy, as well as Forcite annealing molecular dynamics simulations. The AsANT can act as bandgap narrowed non-magnetic semiconductors or highly spin-polarized magnetic semiconductors (half-semiconductor or bipolar magnetic semiconductor) depending on TM types, suggesting different promising applications such as developing infrared photodetectors with broadband detectionin or spintronic devices. The magnetic thermal stability beyond room temperature is predicted for doped tubes. Furthermore, the carrier mobility of AsANTs can be tuned into a wide region by TM doping, but it is enhanced in most cases. The carrier and spin polarity of mobility can also be clearly observed. Particularly, the applied strain can induce a rich magnetic phase transition among a half-semiconductor, half-metal, bipolar magnetic semiconductor and nonmagnetic state. Furthermore, the presented stepwise change of total magnetic moment between high magnetized and nonmagnetic states is highly desirable for engineering a mechanical switch which can reversibly work between magnetism and demagnetism to control spin-polarized transport by applying strain.

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