Vapor-liquid-solid synthesis and characterization of alpha-monoclinic selenium nanowires

Nanowires of alpha-monoclinic Selenium have been synthesized using a physical vapor-liquid-solid (VLS) process for first time. We used micron sized particles of crystalline Antimony Selenide as catalyst and molten Selenium to generate the vapor source. The synthesized nanowires have diameters in the range between 20 nm and 1 microm and lengths up to 30 microm. Nanowires with diameters of approximately 50 nm are the most predominantly produced. Transmission Electron Microscopy (TEM), Micro-Raman Spectroscopy, Absorption Spectroscopy, Energy Dispersive X-ray Analysis (EDAX), High-Resolution Transmission Electron Microscopy (HRTEM) and Selected Area Electron Diffraction (SAED) were used to characterize their morphology, composition and crystallographic structure. It is found that the nanowires grow perpendicular to the (053) plane and exhibit an energy band-gap of 2.2 eV (a 0.18 eV increase compared to bulk).