[Study on the Photoluminescence Properties of Tb Doped Si Nanowires]

Silicon nanowires with high density, uniform distribution and large area were produced directly from Si(100) based on solid-liquid-solid mechanism under the growth temperature of 1 100 ℃ with 30 min. The flow of N2 is 1 500 sccm and Au-Al films is used as metallic catalyst. The diameters of Si nanowires is 50~120 nm and the lengths of the formed Si nanowires is hundreds of nanometers. After that Tb-doped Si nanowires were reserched. We experimentally investigated the influences of the different process parameters on the luminescence of Tb-doped Si nanowires.The main process parameters includ doping temperature(1 000~1 200 ℃), doping time (30~90 min) and gas flow rate of N2 (0~1 000 sccm). Finally, Tb-doped bulk silicon substrates have been studied experimentally. We characterized and analyzed the photoluminescence properties of Tb-doped Si nanowires with the Hitachi F-4600 fluorescence spectrophotometer. The corresponding relation of energy level structure and transition properties of Tb ion with the experimental spectrum is analyzed in detail. The experiment result indicates that the Tb-doped Si nanowires have a stronly green luminescencent. The emission peak position of the largest intensity at 554 nm (5D4→7F5) with the doping temperature 1 100 ℃, the flow of N2 1 000 sccm and the excitation wavelength 243 nm. At the same time,three emission bands of 494 nm (5D4→7F6), 593 nm (5D4→7F4) and 628 nm (5D4→7F3) were observed under room temperature. The Tb-doped Si nanowires appeared strong green light emission compared with the bulk silicon substrate. Its application has a certain reference value for studying the characteristics of luminescence of rare earth element doped Si based material. Meanwhile,the photoluminescence properties of Tb-doped Si nanowires affected by the diameter, length, distribution and density of Si nanowires. That is necessary forour further research.