Synthesis and photoluminescence property of boron carbide nanowires

Large scale, high density boron carbide nanowires have been synthesized by using an improved carbothermal reduction method with B/B$_{2}$O$_{3}$/C powder precursors under an argon flow at 1100${^\circ}$C. The boron carbide nanowires are 5--10\,$\mu $m in length and 80--100\,nm in diameter. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) characterizations show that the boron carbide nanowire has a B$_{4}$C rhombohedral structure with good crystallization. The Raman spectrum of the as-grown boron carbide nanowires is consistent with that of a B$_{4}$C structure consisting of B$_{11}$C icosahedra and C-B-C chains. The room temperature photoluminescence spectrum of the boron carbide nanowires exhibits a visible range of emission centred at 638\,nm.