LAUSR

The thinnest beryllium nanowires with high strength and uniformity are theoretically constructed of connected Be6 octahedron units. Based on this, Ca- and Mg-doped beryllium nanowires are successfully constructed and researched. They are unusual all-metal charge transfer salts Ca2+(Be6)n4-Mg2+ (n = 1-7), and they surprisingly display considerable second-order nonlinear optical (NLO) responses (β0e = 1.05 × 104-1.12 × 105 au). This is because the effect of doping Ca and Mg atoms brings great increase in β0e. In addition, more notably, the effect of the nanowire length on β0e revealed that the β0e value gradually and rapidly increases with the increase in the number of Be6 octahedron units (n). Thus, these doped beryllium nanowires are a new class of NLO nanowires. Fortunately, these NLO nanowires possess working wavebands in the infrared (IR, >2800 nm) and ultraviolet (UV, <200 nm) regions. Then, these doped beryllium NLO nanowires could also be used as new hot IR and UV NLO materials. Considering the dispersion effect, the frequency-dependent value of the electro-optical Pockels effect (EOPE) βe(-ω; ω, 0) at ω = 0.005 au is slightly larger than the corresponding value of β0e. Significantly, the effect of the nanowire length on βe(-ω; ω, 0) is also displayed. Obviously, a new design strategy of enhancing NLO responses by increasing n was obtained. Noticeably, the nanowires display Janus electronic properties of both stronger electron-donating and electron-withdrawing behaviors. This work predicts that novel metal nanowires may be applied in new hot IR and UV NLO materials as well as molecular electronic devices.