Properties of GaAs nanoclusters deposited by a femtosecond laser
Properties of GaAs nanoclusters deposited by a femtosecond laser
复制标题
DOI：
10.1023/a:1019680111363
复制
发表时间：
2002-09-15
影响因子：
4.5
通讯作者：
Reimer, JA
中科院分区：
文献类型：
--
作者：
Dinh, LN;Hayes, SE;Reimer, JA
研究了飞秒脉冲激光沉积GaAs纳米团簇的性能。用激光在真空或氩气中烧蚀单晶GaAs靶材，制备了GaAs纳米团簇。原子力和透射电子显微镜观察表明，团簇大部分呈球形，直径在1 ~ 50 nm之间，峰尺寸分布在5 ~ 9 nm之间，这取决于氩气压力或激光辐照量。x射线衍射、固体核磁共振、俄歇能谱、电子能量损失能谱和高分辨率透射电子显微镜显示，这些纳米团簇是随机取向的砷化镓晶体。随后，由于在空气中的运输，纳米晶体表面形成了类似于2纳米的氧化外壳。未钝化的砷化镓纳米团簇没有可检测到的光致发光。表面钝化后，这些纳米团簇的光致发光能量低于制备它们的大块砷化镓。我们的光致发光实验表明，这些砷化镓纳米晶体中存在丰富的亚带隙表面态。(C) 2002年Kluwer学术出版社。
The properties of femtosecond pulsed laser deposited GaAs nanoclusters were investigated. Nanoclusters of GaAs were produced by laser ablating a single crystal GaAs target in vacuum or Ar gas. Atomic force and transmission electron microscopies showed that most of the clusters were spherical and ranged in diameter from 1 nm to 50 nm, with a peak size distribution between 5 nm and 9 nm, depending on the Ar gas pressure or laser fluence. X-ray diffraction, solid-state nuclear magnetic resonance, Auger electron spectroscopy, electron energy loss spectroscopy, and high-resolution transmission electron microscopy revealed that these nanoclusters were randomly oriented GaAs crystallites. An oxide outer shell of similar to2 nm developed subsequently on the surfaces of the nanocrystals as a result of transportation in air. Unpassivated GaAs nanoclusters exhibited no detectable photoluminescence. After surface passivation, these nanoclusters displayed photoluminescence energies less than that of bulk GaAs from which they were made. Our photoluminescence experiments suggest an abundance of sub-band gap surface states in these GaAs nanocrystals. (C) 2002 Kluwer Academic Publishers.