GaAsP-GaAs nanowire quantum dots for novel quantum emitters

用于新型量子发射器的GaAsP-GaAs纳米线量子点

• 批准号: EP/P000967/1
• 负责人: David Mowbray
• 金额: $ 62.68万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FP000967%2F1
• 关键词: GaAsP; GaAs; nanowire; quantum; dots

Semiconductors are able to efficiently convert electrical energy into light; this is the basis of light emitting diodes (LEDs) and semiconductor lasers. Such devices produce classical light, consisting of many trillions of photons every second. However there are applications in quantum computing and cryptography which require non-classical light, for example a regular stream of single photons or entangled photon pairs; two spatially separated photons which form a single quantum system. Such non-classical light can be created by semiconductor quantum dots; semiconductor nanostructures in which the size of the semiconductor in any dimension is no greater than a few 10's nanometres. Electrons trapped within a quantum dot are unable to move; resulting in dramatically different properties compared to conventional bulk semiconductors in which free electron motion is possible. In addition to the production of non-classical light quantum dots can be used to improve the performance of both lasers and solar cells.There are a number of approaches for the formation of quantum dots. The most studied is self-assembly where the dots form spontaneously on a semiconductor surface; this process is driven by the strain that results when the deposited semiconductor has a different atomic spacing to that of the underlying semiconductor. However the spontaneous nature of this process results in the quantum dots having a distribution in their shape and size; no two dots are identical. In addition controlling the position at which the dots form is very difficult. Recently the formation of quantum wires which grow vertically upwards from a semiconductor surface has been demonstrated. Growth of these wires is initiated either by initially depositing tiny metal droplets on the surface or by forming nanoscale holes in an oxide mask. The quantum wires can have lengths in excess of 1um and diameters below 100nm. During the growth of the quantum wire it is possible to change the semiconductor type and hence insert a small disk of a different semiconductor within the quantum wire. This disk forms a quantum dot and it is this new type of quantum dot that forms the subject of our research.These so-called nanowire quantum dots have a number of significant advantages in comparison to self-assembled ones. For example their position can be accurately controlled by placing the hole in the oxide mask at the desired position. There is also much greater control of the quantum dot shape and size; one consequence of this is the possibility to form many closely spaced identical dots within the wire. Such vertical stacking of quantum dots is not possible in the self-assembled system but is advantageous in lasers where a large number of quantum dots are required to achieve sufficient amplification of the light. In addition the nanowire acts as a cavity to confine photons, allowing the fabrication of nanoscale lasers. Nanowire quantum dots is a very immature field and significant growth development complemented by extensive optical and structural characterisation is required to optimise their properties for a range of applications. We will develop the system based on GaAs quantum dots in GaAsP nanowires grown by molecular beam epitaxy on silicon substrates. Growth on silicon is important as it provides the potential for integration with conventional electronics. Structures will be characterised by transmission electron microscopy and optical spectroscopy of single nanostructures. Following optimisation we will develop structures for a number of applications, including sources of single photons and entangled photon pairs, and nanoscale lasers. We will initially develop devices which are excited by light from a laser but a major later aim is to achieve all electrical devices.

半导体能够有效地将电能转化为光;这是发光二极管（LED）和半导体激光器的基础。这种设备产生经典光，每秒由数万亿个光子组成。然而，量子计算和密码学中的应用需要非经典光，例如单光子或纠缠光子对的规则流;形成单个量子系统的两个空间分离的光子。这种非经典光可以由半导体量子点产生;半导体纳米结构，其中半导体在任何维度上的尺寸不大于几十纳米。被困在量子点内的电子无法移动;与传统的体半导体相比，这导致了显着不同的性质，其中自由电子运动是可能的。除了产生非经典光之外，量子点还可以用来改善激光器和太阳能电池的性能。研究最多的是自组装，其中点自发地形成在半导体表面上;这个过程是由当沉积的半导体具有与底层半导体不同的原子间距时产生的应变驱动的。然而，这个过程的自发性质导致量子点在它们的形状和大小上具有分布;没有两个点是相同的。此外，控制点形成的位置也非常困难。最近，已经证明了从半导体表面垂直向上生长的量子线的形成。这些线的生长要么通过最初在表面上沉积微小的金属液滴，要么通过在氧化物掩模中形成纳米级的孔来启动。量子线的长度可以超过1 μ m，直径可以小于100 nm。在量子线的生长期间，可以改变半导体类型，因此在量子线内插入不同半导体的小圆盘。这个圆盘形成了一个量子点，正是这种新型的量子点形成了我们的研究对象。与自组装量子点相比，这些所谓的纳米线量子点具有许多显著的优势。例如，可以通过在氧化物掩模中的期望位置处放置孔来精确地控制它们的位置。对量子点的形状和大小也有更大的控制;这样做的一个结果是有可能在导线内形成许多紧密间隔的相同点。量子点的这种垂直堆叠在自组装系统中是不可能的，但在需要大量量子点以实现光的充分放大的激光器中是有利的。此外，纳米线作为一个空腔来限制光子，允许制造纳米激光器。纳米线量子点是一个非常不成熟的领域，需要通过广泛的光学和结构表征来补充显着的增长发展，以优化其在一系列应用中的特性。我们将发展以分子束磊晶法在矽基板上成长砷化镓磷奈米线中的砷化镓量子点为基础的系统。硅上的生长是重要的，因为它提供了与传统电子产品集成的潜力。结构将通过单个纳米结构的透射电子显微镜和光学光谱来表征。在优化之后，我们将为许多应用开发结构，包括单光子源和纠缠光子对，以及纳米级激光器。我们最初将开发由激光激发的设备，但后来的主要目标是实现所有电气设备。

项目成果

Defect-Free Axially Stacked GaAs/GaAsP Nanowire Quantum Dots with Strong Carrier Confinement.

• DOI: 10.1021/acs.nanolett.1c01461
• 发表时间: 2021-07-14
• 期刊: Nano letters
• 影响因子: 10.8
• 作者: Zhang Y;Velichko AV;Fonseka HA;Parkinson P;Gott JA;Davis G;Aagesen M;Sanchez AM;Mowbray D;Liu H
• 通讯作者: Liu H

Highly Strained III-V-V Coaxial Nanowire Quantum Wells with Strong Carrier Confinement

• DOI: 10.1021/acsnano.9b01775
• 发表时间: 2019-05-01
• 期刊: ACS NANO
• 影响因子: 17.1
• 作者: Zhang, Yunyan;Davis, George;Liu, Huiyun
• 通讯作者: Liu, Huiyun

Self-Catalyzed AlGaAs Nanowires and AlGaAs/GaAs Nanowire-Quantum Dots on Si Substrates.

• DOI: 10.1021/acs.jpcc.1c03680
• 发表时间: 2021-07-08
• 期刊: The journal of physical chemistry. C, Nanomaterials and interfaces
• 作者: Boras G;Yu X;Fonseka HA;Davis G;Velichko AV;Gott JA;Zeng H;Wu S;Parkinson P;Xu X;Mowbray D;Sanchez AM;Liu H
• 通讯作者: Liu H

Long-Term Stability and Optoelectronic Performance Enhancement of InAsP Nanowires with an Ultrathin InP Passivation Layer.

超薄INP钝化层的长期稳定性和光电性能增强INASP纳米线。

• DOI: 10.1021/acs.nanolett.2c00805
• 发表时间: 2022-04-27
• 期刊: NANO LETTERS
• 影响因子: 10.8
• 作者: Chen, LuLu;OAdeyemo, Stephanie;Fonseka, H. Aruni;Liu, Huiyun;Kar, Srabani;Yang, Hui;Velichko, Anton;Mowbray, David J.;Cheng, Zhiyuan;Sanchez, Ana M.;Joyce, Hannah J.;Zhang, Yunyan
• 通讯作者: Zhang, Yunyan

GaAsP nanowires containing intentional and self-forming quantum dots

• DOI: 10.1117/12.2543747
• 发表时间: 2020-03
• 作者: H. Fonseka;A. Velichko;Yunyan Zhang;G. Davis;James A. Gott;T. Godde;A. Sánchez;R. Beanland