CAREER: Developing Advanced Morphological Control of Nanowires to Encode Photonic and Optoelectronic Functionality

职业：开发纳米线的先进形态控制以编码光子和光电功能

• 批准号: 1555001
• 负责人: James Cahoon
• 金额: $ 55万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1555001&HistoricalAwards=false
• 关键词: CAREER; Developing; Advanced; Morphological; Control

Nontechnical Description: Semiconductor nanowires have been widely explored for their potential electronic and photonic applications, and the properties of the wires are largely dictated by the ability to modulate their composition during synthesis. This project aims to explore chemistry-based processes to encode complex cylindrical silicon wires and to understand the incorporation of phosphorus, boron, and nitrogen dopant atoms in silicon nanowires during their growth. The effect of wire synthesis conditions on the concentration and spatial profiles of these dopant atoms is studied, and the potential for atomically-abrupt interfaces is evaluated. In addition, the influence of the dopant atoms on the optical properties and shape of the wires is examined, targeting optimized growth of spiraling nanowires and controllable creation of luminescent centers within the wires. The project trains undergraduate and graduate students in topics that bridge the interface between chemistry, physics, and engineering - providing breadth of experience in nanomaterials synthesis, microfabrication, optoelectronic measurements, and modeling. Various programs and demonstrations in elementary schools and local libraries, annual public science expositions and summer research for high-school students enable broad dissemination of the scientific concepts. Technical Description: Semiconductor nanowires are often synthesized by metal-catalyzed growth using vapor-liquid-solid (VLS) and vapor-solid-solid (VSS) growth processes. This project aims to develop a combined VLS-VSS growth method to encode phosphorus, boron, and nitrogen dopant atoms in silicon nanowires with single or sub-nanometer spatial resolution. The incorporation of dopants is used to modulate the optical properties and morphology of the nanowires. For instance, co-doping is explored as a novel method to create chiral wires, and the chiro-optical response of these structures is studied. In addition, the incorporation of nitrogen is used to introduce defect states with luminescent characteristics. Modulation of boron and phosphorus is employed to create deep-subwavelength photonic crystal cavities integrated with p-n junction photodetectors that exhibit wavelength-selective detection. These efforts expand the set of bottom-up synthetic methods that can be used to encode photonic and optoelectronic functionality in nanowires.

非技术描述：半导体纳米线因其潜在的电子和光子应用而被广泛探索，并且纳米线的特性很大程度上取决于合成过程中调节其成分的能力。该项目旨在探索基于化学的工艺来编码复杂的圆柱形硅线，并了解磷、硼和氮掺杂剂原子在硅纳米线生长过程中的结合情况。研究了线合成条件对这些掺杂剂原子的浓度和空间分布的影响，并评估了原子突变界面的潜力。此外，还检查了掺杂剂原子对线的光学性质和形状的影响，目标是螺旋纳米线的优化生长和线内发光中心的可控创建。该项目对本科生和研究生进行化学、物理和工程之间桥梁的主题培训，提供纳米材料合成、微加工、光电测量和建模方面的丰富经验。小学和当地图书馆的各种项目和演示、年度公共科学博览会和高中生暑期研究使科学概念得以广泛传播。技术描述：半导体纳米线通常通过金属催化生长，采用气-液-固 (VLS) 和气-固-固 (VSS) 生长工艺来合成。该项目旨在开发一种组合的 VLS-VSS 生长方法，以单纳米或亚纳米空间分辨率编码硅纳米线中的磷、硼和氮掺杂原子。掺杂剂的掺入用于调节纳米线的光学性质和形态。例如，共掺杂被探索作为一种创建手性线的新方法，并研究了这些结构的手性光学响应。此外，氮的掺入用于引入具有发光特性的缺陷态。采用硼和磷的调制来创建与具有波长选择性检测功能的 p-n 结光电探测器集成的深亚波长光子晶体腔。这些努力扩展了一系列自下而上的合成方法，可用于编码纳米线中的光子和光电功能。