Pb离子辐照注碳a-SiO_2薄膜的光致发光性能

Photoluminescence effects of a-SiO_2 films implanted with C ions and irradiated by Pb ions

用湿氧化法在单晶硅表面生长了非晶态SiO2薄膜,进行120 keV C离子注入和950 MeV Pb离子辐照,用荧光光谱分析样品发光特性的改变。结果发现,C离子注入和高能Pb离子辐照均能显著影响样品的发光特性,且荧光光谱的改变强烈依赖于注入和辐照剂量,预示不同注入和辐照剂量将导致不同的发光结构形成。对注入和辐照造成薄膜发光的可能来源及发光改变的机制进行了讨论。

Amorphous SiO2 films of about 1 μm in thickness were thermally grown on single crystalline silicon. The samples were implanted at room temperature （RT） with 120 keV C ions to doses ranging from 1.0 × 10^16to 8.6× 10^17 ions/cm2, and then irradiated at RT with 950 MeV Pb ions to 5.0× 10^11, 1.0 × 10^12 and 3.8 × 10^12 ions/cm2, respectively. Photoluminescence （PL） properties of the samples were investigated using a fluorescent spectroscopy at RT. The results show that Pb ion irradiation affected significantly the PL properties, which depended strongly on doses of the C ion implantation and Pb ion irradiation. For example, huge PL peaks at about 2.89 eV and 2.53 eV could be seen in PL spectra of the sample implanted with 5.0 × 10^11C ions/cm2 and irradiated by 3.8 × 10^12 Pb ions/cm2. This suggests that micro-structure like 6H-SiC may be induced in the C ion-implanted and Pb ion-bombarded a-SiO2 films. It seems that special light emitters can be produced by combined ion implantation and irradiation, which is a useful way for synthesizing new type of SiO2-based light-emitting materials.