Unique optical and electrical properties of silicon-containing heteronanocluster which has three dimensional superlattice structure

研究了具有纳米核和有机侧链的Si和Ge纳米团簇的新合成及其电学和光学性质。由于有机侧链的存在，这种团簇可以溶于常见的有机溶剂，并且由于纳米团簇的Si和Ge晶格的存在，这些团簇表现出了半导体性质。以有机硅和锗纳米团簇为基本单元设计的新材料的研究。研究了有机硅和锗纳米团簇的量子尺寸效应以及硅和锗纳米团簇之间Si/Ge异质结的形成。在四氢呋喃中形成分散的Si和Ge核后，分别加入烷基溴来取代SiMgCl和GeMgCl.拉曼光谱观察到共聚反应形成了Si-Si键、Si-Ge键和Ge-Ge键。通过时间分辨发射光谱，观测到了发射极大值和发射寿命的显著量子尺寸效应。有机硅团簇和锗团簇在可见光区显示出较宽的发射带。根据时间分辨发射光谱和分子轨道计算，讨论了该发射带的来源。在分支点附近形成的扭曲激发态被认为是发射点，其起因是大的斯托克斯位移。衰变分析表明，Si/Ge纳米团簇中存在能量迁移现象。采用旋涂技术制备了有机硅和锗团簇的薄膜。通过热处理、等离子体辐照、激光退火热处理等方法，可以将有机硅和锗团簇薄膜分别转化为无机硅和锗薄膜。这种技术提供了通过涂层来形成c-Si、c-Ge和c-Si/Ge薄膜。

The novel synthesis and the electrical and optical properties of Si and Ge nanoclusters which have nanometer sized core and organic side chains have been studied. Such clusters are soluble in common organic solvents due to the organic side chains and show semiconducting properties due to the Si and Ge lattices of the nanoclusters. The studies of the new materials designed from the organo-silicon and germanium nanoclusters using a basic unit. The quantum size effect of the organo-silicon and germanium nanoclusters and the formation of Si/Ge heterojunction between Si and Ge nanoclusters are investigated. After the formation of Si and Ge core dispersed in THF, an alkylbromide was added to substituted the SiMgCl and GeMgCl, respectively. The formation of Si-Si, Si-Ge, and Ge-Ge bonds by copolymerization were observed by Raman spectroscopy. By the time-resolved emission spectroscopy, significant quantum size effects were observed in the measurements of emission maxima and emission lifetimes. The organo-silicon and germanium cluster showed a broad emission bands in visible region. The origin of the emission band was discussed based on the time-resolved emission spectra and molecular orbital calculations. The distorted excited state formed around the branching point was assigned as the emission site and the origin the large stokes shift. The decay analysis suggests the energy migration in the Si/Ge nanocluster. The thin film of the organo-silicon and germanium clusters were prepared by spin-coating technique. By heat treatment, plasma irradiation, laser annealing, and so on, the organo-silicon and germanium cluster films can be converted to inorganic Si and Ge films, respectively. Such a technique provides the formation of c-Si, c-Ge, and c-Si/Ge films by coating.