Short-living excitations and relaxation processes in ion-implanted and ion beam-mixed silica-silicon systems for optoelectronic application

该项目致力于研究低维氧化物体系和块体纳米结构材料在电离辐射处理下激发态的电子结构和动力学。该项目的主要目标是研究含有辐射缺陷、纳米团簇和纳米晶体的二氧化硅薄膜、非晶态和纳米结构修饰的二氧化硅和硅基材料中短寿命能态的物理性质和演化及其发光特性。该项目的现状是基于为光电子、光电子和光伏行业设计新的功能结构的新可能性，这些新功能结构可以提供更好的信息处理性能。我们将研究不同原子无序度和维度的二氧化硅(玻璃、微晶玻璃和薄膜厚度为20-500 nm)在电子辐照下注入Si、Ge、C、Sn、Pb、Zn离子的不同改性。尤其是离子束混合的SiO_2/Si界面，需要用电子显微镜、扫描电子显微镜和电子能谱等方法进行研究。注入的Si+离子的最大浓度将位于SiO_2-Si界面区附近，导致离子束混合渐变的SiO_x(2&gt；x&gt；0)缓冲区，掺杂注入的离子甚至在离子注入过程中通过原子碰撞(敲除和敲击过程)延伸到硅衬底。涉及光学活性纳米团簇的局域电子态、结合到二氧化硅及其类似物的离子修饰的点缺陷和聚集体的快耗散过程的动力学和机制。计划使用光学非稳态光电子能谱、脉冲光致发光和阴极发光等方法，在研究原子和缺陷团簇及其随尺寸、注入条件和辐照后处理制度的演化过程中都显示出很高的信息检索能力。同步辐射光源和脉冲电子束加速器将被用来研究表面短寿命激发态行为的规律。为了理解高能激发态的本质，将使用一种综合的方法，包括最先进的时间分辨光谱技术和计算机模拟。

The project is devoted to the investigation of the electronic structure and dynamics of the excited states for both the low-dimensional oxide systems and bulk nanostructured materials subjected to ionizing radiation treatments. The main goal of the project is to study the physical nature and evolution of short-living energy states and their luminescence features within thin-films, amorphous and nanostructured modifications of silicon dioxide and silicabased materials containing radiation defects, nanoclusters and nanocrystals. The actuality of the project proposed is based on the new possibilities for new functional structures design for optoelectronics and photonics as well as photovoltaic industries which could provide a better information processing performance. The different silica modifications with varying atomic disorder and dimensionality (glasses, glass ceramics and thin films 20 - 500 nm thick) irradiated by electrons and implanted with Si, Ge, C, Sn, Pb, Zn ions will be the samples under study. Especially the ion beam-mixed Si02/Si interfaces should be investigated by electron microscopic methods EFTEM, STEM imaging, and EELS spectroscopy. The maximum concentralion of implanted Si+ ions will be located near the SiO2-Si interface region leading there to an ion beam mixed gradual SiOx (2 > x > 0) buffer region, doped with implanted ions which is even extended into the Si substrate by atomic collisions (knocking-off and knocking-on processes) during ion implantation.The dynamics and mechanisms of the fast dissipative processes involving the localized electronic states of optically-active nanoclusters, point defects and aggregates incorporated into the ion-modified matrices of silicon dioxide and its analogs. It is planned to use the methods of optical non-stationary photoelectron spectroscopy, pulse photo- and cathodoluminescence which all have shown their high information retrieving ability during the investigations of atom and defect clusters and their evolution depending on size, implantation conditions and post-irradiation treatment regimes. The synchrotron radiation source as well as pulsed electron beam accelerators will be used to study the regularities of the surface short-lived excited states behavior. In order to understand the nature of highenergy excited states a combined approach will be used involving both the state-of-the-art time-resolved spectroscopy techniques and computer modeling.