摘要
以液态金属Ga作为催化剂合成了大量的非晶SiO_2纳米线阵列。这些纳米线具有高度取向性,直径分布均匀,平均约8 nm,长度大于300μm。研究发现,载气的湿度对非晶SiO_2纳米线阵列的生长有重大影响,提出了一种可能的生长模型,以解释这一与传统的VLS机制不同的生长过程。对样品的光致荧光(PL)谱的测量表明,非晶SiO_2纳米线阵列在蓝光波段附近存在两个很强且稳定的发射峰,它们直接与样品中的缺陷和空位有关。首次发现了一个稳定的PL峰,存在于红外波段,作为光源,非晶SiO_2纳米线阵列可能会在纳米光电子器件中得到应用。由于SiO_2是传统的光纤材料,单根SiO_2纳米线也有希望应用于近场光学扫描显微镜(SNOM)之中。
Silica nanowire arrays have been synthesized in a large-scale when we successfully grew various Ga_2O_3
quasi one-dimension structures in the tube furnace, via the simple method of heating the metal Ga. The nanowires
are of high purity and highly oriented. Their diameters distribute from 5 nm to 12 nm, with average value of 8 nm
and lengths of 300μm. The analysis shows that they are amorphous.
The experiments show that the liquid Ga acts as the catalyst and the growth of SiO_2 represents some new
characteristics, which traditional VLS mechanism does not own. It was also found that the moisture of the flowing
argon gas is a key factor for the growth of nanowires. A possible growth model of nanowires is proposed upon these,
which is distinctive from the conventional Vapor-liquid-solid (VLS) growth mechanism.
Under the optical excitation of 325 nm laser, the sample exhibits two intensive and stable light emissions near
the blue light wave bond, which are directly related to the defects and vacancies in the sample. Besides these two
peaks, one new infrared peak at about 804 nm was first found in our experiments, whose mechanism is unknown
now and will be researched in further.
As an excellent optical source, the silica nanowire arrays can find applications in future opto-electronic
nanodevices. Additionally, single silica nanowire may be used in scanning near field optical microscope as the alter-
native probes. Finally, because of the high flexibility of the SiO_2 nanowire bundles they can also be used in the
future nano-optical fiber, which is one of important segments in the information transfer. So research in the synthesis
of silica nanowires and the characteristic of PL of them are of remarkable importance.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2004年第2期173-177,共5页
Chinese Journal of Luminescence
基金
国家自然科学基金重点项目
国家杰出青年科学基金
教育部博士点专项基金(50025206
19834080)
