Electronic structure and optical properties of transition metal doped silicon clusters on surfaces - Building blocks for cluster assembled materials

表面过渡金属掺杂硅团簇的电子结构和光学性质 - 团簇组装材料的构建模块

• 批准号: 45036396
• 负责人: Professor Dr. Tobias Lau
• 金额: --
• 依托单位: Arbeitsgruppe Cluster und Nanokristalle (AG Möller)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/45036396?language=en
• 关键词: Electronic; structure; optical; properties; transition

Because of their fascinating properties, doped semiconductor clusters are promising candidates as building blocks for cluster assembled materials. By doping with transition metal atoms, small silicon clusters can be stabilized in endohedral cage structures with exceptional stability. These clusters are characterized by large highest occupied{lowest unoccupied molecular orbital (HOMO-LUMO) gaps, electronic shell closures, and a silicon cage surrounding the dopant atom. According to theoretical predictions, the HOMO-LUMO gap can be controlled by varying both the dopant atom and the host cluster size. There is even experimental evidence of hydrogen-free doped silicon clusters with no dangling bonds at the cluster surface. In this project, we aim at an understanding of the electronic and optical properties of transition metal doped silicon clusters MSin (M=Cr, Ti, W; n < 20) after deposition onto metal and semiconductor substrates. We will focus on special `magic' clusters with chemical stability, which are suited as building blocks for cluster assembled materials. These clusters will be studied by photoluminescence and photoelectron spectroscopy in the laboratory, accompanied by X-ray absorption spectroscopy at synchrotron storage rings. With these methods, we will clarify fundamental issues of cluster photoluminescence and technologically relevant questions of cluster stability on surfaces, as well as possible electroluminescence in deposited clusters.

由于其令人着迷的特性，掺杂半导体团簇是有希望的候选团簇组装材料的构建块。通过掺杂过渡金属原子，小硅团簇可以稳定在具有优异稳定性的内笼结构中。这些团簇的特点是具有较大的最高已占据{最低未占据分子轨道（HOMO-LUMO）间隙、电子壳层闭合和掺杂原子周围的硅笼。根据理论预测，可以通过改变掺杂原子和主簇大小来控制HOMO-LUMO间隙。甚至有实验证据表明，无氢掺杂的硅团簇表面没有悬空键。在这个项目中，我们的目标是了解过渡金属掺杂硅簇MSin （M=Cr, Ti， W; n < 20）沉积在金属和半导体衬底上后的电子和光学性质。我们将重点关注具有化学稳定性的特殊“神奇”团簇，它们适合作为团簇组装材料的构建块。这些团簇将在实验室中通过光致发光和光电子能谱进行研究，同时在同步加速器存储环上进行x射线吸收光谱研究。通过这些方法，我们将澄清团簇光致发光的基本问题和表面团簇稳定性的技术相关问题，以及沉积团簇中可能的电致发光。