Deposition and nonlinear optical properties of transition metal nitride/oxide thin films

过渡金属氮化物/氧化物薄膜的沉积和非线性光学性质

基本信息

批准号：
1905305
负责人：
Theodosia Gougousi
金额：
$ 48万
依托单位：
University of Maryland Baltimore County
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-01 至 2024-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1905305&HistoricalAwards=false
关键词：
Deposition nonlinear optical properties transition

项目摘要

Nontechnical description: The interaction of light with matter is of high scientific and technological interest. Light is an electromagnetic wave and the electric field may interact with the charges present in the material to produce separation of the positive and negative charge centers resulting in the appearance of an electric field within the body of the material. When the intensity of the light is low, then the induced electric field is also very small and proportional (linear) to the applied field. However, when intense light such as that from a laser is used then it is possible that a very high (nonlinear) response may be obtained. This intense response to the externally applied electric field depends on the structure and composition of the material and can be used to generate light of a different color, or to modulate the propagation of light through the material via an intensity dependent refractive index. For example, it is highly desirable to be able to protect sensors and the naked human eye from high intensity light such as lasers. While the military implications of such materials are obvious, the benefits can affect many areas of everyday life. Most of the materials known to have a nonlinear response are cut from large crystals or are liquids and are not suitable to cover large areas reproducibly such as those needed for the application described before. In this project, the research team study a new class of nonlinear optical materials that are based on thin films that can be deposited reliably and reproducibly on large surface areas including complex geometries and even optical fibers with atomic scale precision. The project is training of two graduate students in an area of high technological importance. Technical description: Nonlinear materials in thin film form are highly desirable for on chip fast all-optical switching devices, frequency conversion and optical limiting applications as conventional nonlinear optical materials are not suitable for integration with the contemporary semiconductor industry process flow. This project seeks to address this shortage by designing and investigating novel nonlinear optical materials based on rational principles. The materials investigated are based on titanium and tantalum nitride seeded dielectric thin films where the at% of titanium-nitrogen or tantalum-nitrogen bonding in the film volume can be used to control the value of the nonlinear index of refraction and film transparency. The maturation of ALD as a thin film deposition technique allows the formation of such structures with atomic level thickness control, through a single deposition process by just controlling parameters such as the process temperature and the precursor delivery temperature. This project includes design of seeded materials with tunable composition, as well as the adaptation of optical techniques such as Z-scan and ultrafast pump-probe to investigate these novel, ultrathin structures. The proposed activity and the interdisciplinary research team seek to combine and transfer knowledge between the electronics materials and nonlinear optics communities. Such cross pollination is expected to advance the state of the art in both fields, with the goal to enrich the materials toolkit available for on chip fast all-optical switching, frequency conversion and optical limiting applications. The main outcome for this proposal is to provide detailed understanding of the physics governing a new class of semiconductor compatible nonlinear optical materials that may address the technological need for novel, well-characterized materials to aid in the realization of new device paradigms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术描述：光与物质的相互作用具有很高的科学和技术感兴趣。光是电磁波，电场可能与材料中存在的电荷相互作用，以产生正电荷中心和负电荷中心的分离，从而导致材料体内的电场出现。当光强度低时，诱导的电场也很小，并且与所施加的场成比例（线性）。但是，当使用激光诸如激光之类的强光时，可能会获得很高（非线性）的响应。对外部施加的电场的这种强烈反应取决于材料的结构和组成，可用于产生不同颜色的光，或者通过强度依赖性折射率通过材料通过材料调节光的传播。例如，高度希望能够保护传感器和肉眼免受激光等高强度光线的影响。尽管这种材料的军事含义是显而易见的，但好处可能会影响日常生活的许多领域。大多数已知具有非线性响应的材料是从大晶体或液体中切割的，不适合覆盖大面积，例如以前所述的应用所需的材料。在该项目中，研究团队研究了一类新的非线性光学材料，这些材料基于薄膜，这些薄膜可以可靠地沉积在大型表面积上，包括复杂的几何形状，甚至具有原子尺度精度的光纤。该项目是对两名研究生的培训。技术描述：薄膜形式的非线性材料非常需要在芯片上快速全光开关设备，频率转换和光学限制应用，因为传统的非线性光学材料不适合与当代半导体行业过程流动。该项目旨在通过根据理性原则设计和调查新颖的非线性光学材料来解决这一短缺。所研究的材料基于钛和硝酸钛种子介电薄膜，其中薄膜体积中的AT％钛氮或坦塔尔氮键合粘合，可用于控制折射和膜透明度的非线性指数的价值。 ALD作为薄膜沉积技术的成熟允许通过单个沉积过程来形成具有原子水平厚度控制的此类结构，仅通过控制参数，例如过程温度和前体递送温度。该项目包括具有可调成分的种子材料的设计，以及光学技术（例如Z-SCAN和Ultrafast Pump-probe）的适应，以研究这些新颖的超薄结构。拟议的活动和跨学科研究团队试图将电子材料和非线性光学群落之间的知识结合起来。预计这种交叉授粉将推进两个领域的最新技术，其目标是丰富用于芯片快速全光开关，频率转换和光学限制应用程序的材料工具包。该提案的主要结果是对管理新的半导体兼容的非线性光学材料的物理学提供详细的了解，该材料可能满足新型，良好的材料的技术需求，以帮助实现新设备范式。 NSF的法定使命，并使用基金会的知识分子优点和更广泛的影响审查标准来评估值得支持。