Cooperative Atomic Dynamics in Crystalline Cages - From Defect Complexes To Self-assembled Nanostructures

9803768潘特利德斯该奖项支持对原子级机制的电子结构理论研究，原子级机制是纳米级结构成核和生长的基础。PI以前的工作表明，对缺陷复合体的研究可以预测点缺陷或缺陷复合体的潜在自组装、新颖的有序结构。这些结构对应于导致低配位的“化学”和通常决定高配位的“结晶度”之间的微妙平衡。拟议的研究涉及对特定系统的调查，选择这些系统是因为缺陷复合体对材料的电学和光学性质的预期影响；证明或预期的具有纳米器件或纳米线潜力的有序结构的自组装；预期的“化学”和“结晶度”之间的新的相互作用；或这些标准的任何组合。例如，在硅中可能存在有序的F杂质，这可能导致嵌入纳米线，以及可能控制低温生长的GaAs的性质和观察到的有序球形As沉淀的自组装的As络合物的成核和生长。PI将对原子长度尺度进行计算研究，以确定材料中的特定缺陷如何影响其电子和光学性能，以及如何将所需的缺陷引入材料。有目的地操纵材料中的缺陷结构以产生特定的性能，为原子尺度上的电子设备的“工程”带来了希望。***

9803768 Pantelides This award supports electronic structure theory investigations of atomic-scale mechanisms that underlie the nucleation and growth of nano-scale structures. The PI's previous work has shown that the study of defect complexes can lead to the prediction of potentially self-assembled, novel, ordered structures of point defects or defect complexes. These structures correspond to a subtle balance between `chemistry' that leads to low coordination and `crystallinity' that generally dictates high coordination. The proposed research entails the investigation of specific systems, selected because of the anticipated effect of defect complexes on the material's electrical and optical properties; the demonstrated or anticipated self-assembly of ordered structures with potential for nanodevices or nanowires; anticipated novel interplay between `chemistry' and `crystallinity'; or any combination of these criteria. Examples include the possibility of ordered F impurities in Si that may lead to embedded nanowires and the nucleation and growth of As complexes that may control both the properties of the low-temperature-grown GaAs and the observed self-assembly of ordered spherical As precipitates. %%% The PI will perform computational research on atomic length scales to determine how specific defects in materials affect their electronic and optical properties and how desirable defects can be introduced into a material. The purposeful manipulation of defect structures in materials to produce specific properties holds promise for the `engineering' of electronic devices on the atomic scale. ***