Vapor–liquid–solid growth and narrow-band ultraviolet photoluminescence of well-aligned GeO₂ nanowire arrays with controllable aspect ratios

摘要

GeO₂ nanowire arrays have been fabricated by thermal evaporation of Ge powder in air via a vapor–liquid–solid mechanism with Au as a catalyst. The GeO₂ nanowires are single crystalline with a hexagonal structure and have a controllable aspect ratio in the range of 23–167. The controllable synthesis of GeO₂ nanowire arrays with different aspect ratios was achieved by adjusting the heating temperature and time. Photoluminescence spectra of the GeO₂ nanowire arrays were measured at room temperature, and two ultraviolet emission peaks at 347 and 364 nm are observed for the first time, which indicates that the GeO₂ nanowire arrays may have potential applications in nanoscale photonic and electronic devices. Moreover, this vapor–liquid–solid growth process may be employed for synthesis of the highly oriented nanowire arrays of other oxides, and provides opportunities for both fundamental research and technological applications.