[en] Bilayer silicene (BLS) is a class of material that possibly holds both topological and superconducting properties; however, its structure is not fully understood. By scanning stacking modes and lattice constants using first principles calculations, several meta-stable configurations are identified, including a slightly faulted-AA packing structure, named slide-2AA. Different from the metallic properties of conventional AA and AB stacking forms, band structure of slide-2AA bilayer presents a sizeable indirect energy gap of ∼1.16 eV. A metal-semiconductor phase transition along the sliding pathway with a small energy barrier is also observed, indicating its electronic properties can be easily tuned by applying small shear force along the BLS surface plane. Such unique quantitative relationship of structure and electronic properties has profound implications in nanoelectronics and electromechanical devices

[en] The electronic properties and relative stability of zigzag graphene nanoribbons are studied by varying the percentage of hydroxyl radicals for edge saturation using first principle calculations. The passivated structures of zigzag graphene nanoribbon have spin-polarized ground state with antiferromagnetic exchange coupling across the edge and ferromagnetic coupling along the edges. When the edges are specially passivated by hydroxyl, the potentials of spin exchange interaction across the two edges shift accordingly, resulting into a spin-semiconductor. Varying the concentration of hydroxyl groups can alter the maximum magnetization splitting. When the percentage of asymmetrically adsorbed hydroxyl reaches 50%, the magnetization splitting can reach a value as high as 275 meV due to the asymmetrical potential across the nanoribbon edges. These results would favor spintronic device applications based on zigzag graphene nanoribbons

[en] AgSbTe${}_2$ exhibits superior thermoelectric performance in the mid-temperature region, but its electrical properties are strongly affected by intrinsic defects and secondary phases. Distinctively, the high mobility electrons still play an important role as minority carriers in p-type AgSbTe${}_2$ even below the bipolarization temperature and decrease the Seebeck coefficient. Here, the Al and Se dual alloying can effectively increase the hole concentration by reducing the cation vacancy formation energy and simultaneously reduce the electron concentration by suppressing the n-type Ag${}_2$Te secondary phase are demonstrated, which results in the shift of carrier transport from two-type to one-type as confirmed by Hall measurement. Consequently, through adjusting the ratio of hole and electron conductivity, the average power factor of alloyed sample is enhanced by 70%. Combined with further reduced lattice thermal conductivity resulting from high-density stacking faults and superstructures, a maximum zT of 1.90 and an average zT of 1.42 are obtained in the temperature range of 323 to 623 K in the (AgSbTe${}_2$)${}_{0.98}$(AgAlSe${}_2$)${}_{0.02}$ sample. Finally, based on the finite element analysis modeling results, both single-leg and double-leg thermoelectric devices are fabricated, which show high conversion efficiency of 11.2% and 5.2%, respectively. (© 2024 Wiley‐VCH GmbH)