Preparation and photoluminescence properties of Ce3+-doped Si nanowires

In this paper, silicon nanowires were grown directly from n-(100) single crystal silicon based on solid-liquid-solid mechanism with Au-Al films as metallic catalyst. Then Ce-doped Si nanowires were researched. The influences of the different doping temperatures (1000-1200 °C), doping durations (15-60 min) and gas flow rate of N2(0-1000 sccm) on the luminescence of Ce3+ were experimentally investigated. The morphology and microstructure of the Si nanowires, the photoluminescence properties and growth crystal orientation were characterized and analyzed by the scanning electron microscopy, the Hitachi F-4600 fluorescence spectrophotometer, the FLS-920 full functional fluorescence spectrometer and X-ray powder diffraction. The results show that the Ce-doped Si nanowires have a strong blue luminescencent with an emission peak position at 405 nm (5D → 2F5/2) when the doping temperature is 1200 °C, the grow time of Si nanowires is 30 min and the optimize excitation wavelength is 328 nm. The fluorescence quantum efficiency is as high as 60.57%. The color coordinates of Ce-doped Si nanowires is (0.16, 0.03) based on the distribution of emission spectral and CIE-1931 standard formula. Ce-doped Si nanowires have potential applications in the areas of lighting and display because of its strong luminous intensity and relatively high fluorescence quantum efficiency.