Molecular Models for III-V Quantum Dots

量子点（QD）是半导体的碎片，根据其大小吸收和发射不同颜色的光。它们是纳米级的设备，也就是说，它们比高尔夫球小一百万倍。量子点具有优异的性能，为从太阳能电池板到生物和医学传感以及从电视屏幕到电子产品的广泛应用提供了潜力。然而，其工业化吸收的主要障碍是其具有挑战性的制造。在这些纳米粒子的理想制备中，所有输出的量子点在尺寸上都是相同的-代表完美的质量控制。然而，在实践中，这是很难实现的。在标准方法中，两种材料反应形成一个中心点或原子核，量子点在几分钟内围绕它生长。如果前体的混合不均匀，则这些核在不同的时间形成，因此生长期持续不同的时间长度，导致不同的尺寸。在研究实验室中，这相对容易控制，但在实际的工业规模上，实现瞬时混合非常困难。这导致了对这些惊人材料的使用和制造的低吸收。在这个项目中，我们将开发一种新的合成路线，通过预先准备这些物质，消除了形成核的需要-消除了瞬时混合的需要。这将使我们能够对我们生产的量子点的大小进行完美的质量控制。我们将制备由组成量子点的元素簇组成的化合物，并通过控制生长来优化从这些簇核到量子点的路线。这些簇的第二个优点是它们将具有与量子点相同的原子结构。对于量子点来说，如果不使用极其昂贵的高功率电子显微镜，就很难确定每个原子的确切位置，而这种显微镜在世界范围内只有少数几台。然而，我们可以利用常规的分子技术来确定团簇成分的确切原子位置，例如任何添加剂或它们的表面。在项目的第二部分，我们将开发所谓的量子点分子模型，以允许未来材料的合理设计，并授权更多的研究人员，促进量子点的未来发展。

Quantum dots (QDs) are fragments of semiconductors that absorb and emit different colours of light depending on their size. They are a nanoscale device, that is they are over a million times smaller than a golf ball. Quantum dots have excellent properties that offer the potential for widespread applications ranging from solar panels to biological and medical sensing and from use in television screens to electronics. However, the major barrier to their industrial uptake is their challenging manufacture. In an ideal preparation of these nanoparticles, all of the output quantum dots would be identical in size - representing perfect quality control. In practice however, this is very difficult to achieve. In a standard method, two materials react to form a central point, or nucleus, around which the QD grows in a matter of minutes. If there is non-even mixing of the precursors, then these nuclei form at different times and so the growth period lasts for different lengths of time, resulting in different sizes. In a research laboratory it is relatively easy to control this, but on a practical industrial scale, it extremely hard to achieve instantaneous mixing. This has resulted in a low uptake of the use and manufacture of these amazing materials. In this project, we will develop a new synthetic route that eliminates the need to form nuclei, by preparing these in advance - removing the need for instantaneous mixing. This will enable us to have perfect quality control over the size of the quantum dots that we produce. We will prepare compounds, consisting of a cluster of the elements that make up the quantum dot and optimise the route from these cluster nuclei to QDs by controlling the growth.A secondary advantage of these clusters is that they will have the same atomic structure as the QDs. For quantum dots it can be very hard to determine the exact position of each atom, without using an extremely expensive high-powered electron microscopes, of which there are only a few worldwide. However, we can take advantage of routine molecular techniques to determine the exact atomic positions of the cluster's constituents, such as any additives or their surfaces. In this second part of the project, we will develop so-called molecular models of the QDs, to allow the rationale design of future materials and empower more researchers, facilitating the future development of QDs.