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Excellence in Research: GaAsSb/GaAs Nanowires based Avalanche Photodetectors on Si

卓越的研究：基于 Si 上的 GaAsSb/GaAs 纳米线雪崩光电探测器

基本信息

批准号：
1832117
负责人：
Shanthi Iyer
金额：
$ 50万
依托单位：
North Carolina Agricultural & Technical State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-15 至 2023-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1832117&HistoricalAwards=false
关键词：
Excellence Research GaAsSb GaAs Nanowires

项目摘要

An important building block of the quantum information circuit is the single photon detection device. The avalanche photodetector in the nanowire configuration is a promising route to achieving single photon detection as it enables reduction in the impact ionization region, thus improving gain and detectivity. Further, the relaxation of the lattice mismatch constraint in the nanowire configuration enables integration of the avalanche photodetector to the traditional silicon technology. GaAsSb is an ideal material system for wavelength tunability in the optical communication wavelength range of 1.3 - 1.55 microns. The GaAsSb/GaAs heterostructure will be designed for independent multiplication and absorption regions, with the former occurring in the larger bandgap GaAs junction to minimize the effect of Zener breakdown, which is a common problem in low band gap materials. This proposal's central theme is on the growth and design optimization of the separate optical absorption and multiplication region in the GaAsSb/GaAs nanowire based avalanche photodetector heterostructure on Si. Two different nanowire configurations namely axial and core-shell will be examined using a variety of material and device characterization techniques. The experimental work will be complemented by modeling using different software packages. Emphasis will be on engineering the increase of the electric field in 3D and gaining deeper insight into the avalanche mechanism (multiplication of the carriers) in the two different nanowire configurations. The performance in these two configurations will be evaluated to arrive at an optimized design in the final phase to achieve nano-avalanche photodetector with gain exceeding 10 in the near infrared region. Technical: Avalanche photodetectors are commonly used for high speed, high gain and low optical signal detection applications. The interest in nanowire - based avalanche photodetectors stems from the potential success of single photon detection devices. Nanowire architecture due to its one dimensional attributes leads to unique and novel material properties and concomitantly enables adaptation of fabrication processes from thin film technology. The relaxation of lattice mismatch constraint, small footprint, high surface to volume ratio, superior optical trapping and feasibility of implementing in different nanowire architectures can be strategically used to improve the detector performance and enabling heterogeneous integration with traditional Si technology. In the proposed work, separate optical absorption and multiplication region avalanche photodetector concepts from the thin film form will be adapted toward bandgap engineering of GaAsSb/GaAs heterostructure in a unique manner, exclusive to the nanowire architecture. The GaAsSb material system has been chosen as it encompasses the bandgap tunable in the telecommunication wavelength region. Different design concepts in the implementation of avalanche photodetector will be realized: axial and radial architectures, the latter of which is exclusive to the nanowire configuration. The investigation of nanowire ensemble based avalanche photodetectors enable taking advantage of the vertical alignment that allows superior light trapping properties leading to enhanced optical absorption. The performance in the two different configurations will be evaluated to arrive at an optimized design in the final phase to achieve nano-avalanche photodetector with gain exceeding 10 in the near infrared region. This study will provide deeper insight into the effect of photoconductivity modulation on the avalanche mechanism in nanowires due to the band bending at the surface stemming from the close proximity of the surface to the core of the NW, particularly in axial architecture. Advances made in the heterostructure design toward achieving an increased 3D electric field in a lower dimensional structure will enable transformational improvement in the device performance with significant impact on material and device research.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.

量子信息电路的一个重要组成部分是单光子探测装置。雪崩光电探测器的纳米线配置是一个有前途的路线，以实现单光子检测，因为它能够减少碰撞电离区，从而提高增益和探测率。此外，纳米线配置中的晶格失配约束的放松使得雪崩光电探测器能够集成到传统的硅技术。 GaAsSb是在1.3 - 1.55微米的光通信波长范围内波长可调谐性的理想材料系统。GaAsSb/GaAs异质结构将被设计为独立的倍增区和吸收区，前者发生在较大带隙的GaAs结中，以最大限度地减少齐纳击穿的影响，齐纳击穿是低带隙材料中的常见问题。该提案的中心主题是在Si上的基于GaAsSb/GaAs纳米线的雪崩光电探测器异质结构中分离的光吸收和倍增区域的生长和设计优化。两种不同的纳米线配置，即轴向和核壳将使用各种材料和器件表征技术进行检查。实验工作将通过使用不同的软件包进行建模来补充。重点将放在工程上的电场在3D的增加，并获得更深入的了解雪崩机制（载流子的倍增）在两种不同的纳米线配置。在这两种配置的性能将进行评估，以达到在最后阶段的优化设计，以实现在近红外区域的增益超过10的纳米雪崩光电探测器。技术：雪崩光电探测器通常用于高速，高增益和低光信号检测应用。对基于纳米线的雪崩光电探测器的兴趣源于单光子探测器件的潜在成功。纳米线架构由于其一维属性导致独特和新颖的材料特性，并伴随着使薄膜技术的制造工艺适应。晶格失配约束的放松、小的占用面积、高的表面与体积比、上级光学捕获以及在不同纳米线架构中实施的可行性可以被策略性地用于改善检测器性能并且使得能够与传统Si技术进行异质集成。在所提出的工作中，单独的光吸收和倍增区雪崩光电探测器的概念，从薄膜的形式将适用于GaAsSb/GaAs异质结构的带隙工程以独特的方式，独家的纳米线架构。选择GaAsSb材料系统是因为它包含在电信波长区域中可调谐的带隙。雪崩光电探测器的实现将实现不同的设计概念：轴向和径向架构，后者是专为纳米线配置。基于纳米线系综的雪崩光电探测器的研究使得能够利用允许上级光捕获性质的垂直对准，从而导致增强的光吸收。将评估两种不同配置的性能，以在最后阶段达到优化设计，以实现在近红外区域增益超过10的纳米雪崩光电探测器。这项研究将提供更深入的了解光电导调制的雪崩机制的影响，在纳米线由于带弯曲的表面产生的近距离的表面的NW的核心，特别是在轴向架构。在异质结构设计方面取得的进展，在较低维度的结构中实现了增加的3D电场，这将使器件性能的变革性改进，对材料和器件研究产生重大影响。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Space charge limited conduction mechanism in GaAsSb nanowires and the effect of in situ annealing in ultra-high vacuum

GaAsSb纳米线空间电荷有限传导机制及超高真空原位退火效应

DOI：
10.1088/1361-6528/ab47aa
发表时间：
2020
期刊：
Nanotechnology
影响因子：
3.5
作者：
Parakh, Mehul;Johnson, Sean;Pokharel, Rabin;Ramaswamy, Priyanka;Nalamati, Surya;Li, Jia;Iyer, Shanthi
通讯作者：
Iyer, Shanthi

A Study on the Effects of Gallium Droplet Consumption and Post Growth Annealing on Te- Doped GaAs Nanowire Proper-ties grown by Self-Catalyzed Molecular Beam Epitaxy

镓滴消耗和生长后退火对自催化分子束外延生长的Te掺杂GaAs纳米线性能影响的研究