Epitaxial Ag Island - Ge/Si(100) Quantum Dot Nanocomposites for Enhanced Si-Based Light Emission

技术：该项目旨在赋予硅兼容材料更高的光学功能。将研究在Ge/Si（100）量子点（QD）附近布置Ag岛的外延架构，以评估等离子体对发光效率的增强。局域表面等离子体激元（LSP）模式的银岛的预测，以提高由Ge量子点的光子的吸收和发射。增加的吸收的结果从附近的银纳米粒子的戏剧性的场浓度。珀塞尔效应增加了自发辐射率。最近的理论工作表明，等离子体激元的增强将是最大的最佳安排的Ge点和Ag岛，如果LSP共振频率接近的QD激子。Ag岛的近UV LSP共振将使用形状共振效应的组合并通过改变它们的介电环境来调谐以匹配Ge/Si（100）QD的近IR激子能量。在理想情况下，理论预测的发光增强可以接近两个数量级。一个焦点将是确定覆盖掩埋Ge点的Si层的非均匀应变平面表面是否会影响Ag岛成核的热力学或动力学。第二个焦点将是在硅盖层完成之前，在Ge点上方发现的纳米级凹坑。非技术性：该项目将对参与研究的学生的教育和未来职业产生积极影响。他们将接受等离子体激元学快速发展领域的材料和建筑的合成以及结构和光学表征的培训。此外，链接到非常成功的科学是有趣的程序提供的勒罗伊艾林中心固态科学在亚利桑那州立大学将被建立。这个程序的影响，平均12,000高中和中学生每年。PI将与科学是有趣的工作人员和实习生密切合作，开发动手，年龄适当的活动，展示光与光子结构的相互作用，使用自然发生的蝴蝶翅膀，鸟类羽毛和贝壳？注意力攫取者？

Technical: This project seeks to endow Si-compatible materials with increased optical functionality. Epitaxial architectures that arrange Ag islands in proximity to Ge/Si(100) quantum dots (QDs) will be investigated to assess plasmonic enhancements to luminescence efficiency. The localized surface plasmon (LSP) mode of the Ag island is predicted to improve both the absorption and emission of photons by the Ge QD. Increased absorption results from the dramatic field concentration near the Ag nanoparticle. The Purcell effect increases the spontaneous emission rate. Recent theoretical work suggests that plasmonic enhancements will be greatest for optimally arranged Ge dots and Ag islands if the LSP resonance frequency is close to that of the QD exciton. The near UV LSP resonance of the Ag islands will be tuned to match the near IR exciton energy of the Ge/Si(100) QDs using a combination of shape resonance effects and by varying their dielectric environment. In the ideal case, theory predicts the luminescence enhancement can approach two orders of magnitude.One focus will be to determine whether the inhomogeneously strained planar surface of the Si layer that caps the buried Ge dots can affect the thermodynamics or kinetics of Ag island nucleation. The second focus will be on the nm-scale pits found immediately above the Ge dots just prior to completion of the Si cap layer. Non-technical: this project will positively affect the education and future career of the student(s) involved in the research. They will be trained in the synthesis as well as the structural and optical characterization of materials and architectures in the rapidly growing field of plasmonics. Additionally, links to the highly successful Science is Fun program offered by the Leroy Eyring Center for Solid State Science at ASU will be established.This program impacts on average 12,000 high and middle school students annually. The PI will work closely with Science is Fun staff and interns to develop hands-on, age-appropriate activities that demonstrate interaction of light with photonic structures using naturally occurring butterfly wings, bird feathers and seashells as ?attention grabbers?.