GaN基稀磁材料中磁纳米晶-半导体纳米复合体微观结构与磁、光、电性能研究

项目名称： GaN基稀磁材料中磁纳米晶-半导体纳米复合体微观结构与磁、光、电性能研究

项目编号： No.51272275

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 周桃飞

作者单位： 中国科学院苏州纳米技术与纳米仿生研究所

项目金额： 78万元

中文摘要： 自GaN基稀磁半导体材料存在室温铁磁性理论预言以来，一直备受关注，然而至今人们对其磁性起源及调控仍存在广泛争议。最新研究发现这类材料中因掺杂离子聚集而形成磁纳米晶被认为是这类材料磁性主要来源。如何认识掺杂磁性离子纳米尺度上的聚集机理并调控由此而形成的磁纳米晶的分布、形状、大小，将是GaN基稀磁材料走向最终器件应用过程中必须解决的重要科学问题之一。本项目将通过非磁性离子共掺设计，从电子态调控层面重新认识GaN基稀磁材料中基于载流子诱导的p-d Zener铁磁性产生相关机制；采用具有原子序数衬度的扫描透射电子显微术（STEM），对实验上最近发现的磁纳米晶（铁磁金属）-半导体纳米复合体的微观结构进行进一步的系统表征和分析，最后从多参量耦合角度，探索和分析这种纳米复合体中电场调控下的磁光克尔旋转、磁场调控下的光电响应、光场调控下磁电耦合等潜在物理机制。

中文关键词： 稀磁半导体；铁掺氮化镓；氢化物气相外延；铁离子氮空位复合体；强束缚激子

英文摘要： Prompted by theoretical predictions of room-temperature ferromagnetism，a great deal of effort has been put into the investigation of the mechanisms behind the ferromagnetism of GaN based diluted magnetic semiconductors （DMS） in the past couple of decades. Indeed, a ferromagnetic response persisting up to above room temperature has been reported for GaN based DMS. However, despite the apparent agreement between promising experimental findings and the computation expectations, the origin of ferromagnetism in DMS has started to emerge as the most unsettled question in today's materials science and engineering. Especially the application of state-of-the-art nanocharacterization tools appears to reveal that some condensed magnetic semiconductor (CMS) nanocrystals might be responsible for the ferromagnetism. The kind of ferromagnetic metal/semiconductor nanocomposites offer a spectrum of so far unexplored possibilities in various fields of materials science and device physics. Hence, it will be an unexpectedly challenging issues how to visualize and control the magnetic ion aggregation to develop methods of producing lateral and vertical distributions, as well as different shapes of magnetic nanocrystals. In this project, a series of codoping of GaN based DMS with shallow nonmagnetic impurities will be used to affect

英文关键词： diluted magnetic semiconductors；Fe doped GaN；Hydride vapor phase epitaxy；[Fe2+-VN]复合体；strong bound exciton