Colloidal versus epitaxial quantum confined systems: the influence of a surface on optoelectronic properties of nanomaterials

胶体与外延量子限制系统：表面对纳米材料光电性质的影响

• 批准号: 356166-2008
• 负责人: Allen, Claudine
• 金额: $ 2.22万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=483059
• 关键词: Colloidal; versus; epitaxial; quantum; confined

In the blooming field of nanotechnology, we are still in the infancy of tool development at this small scale. The interaction of these tools with the environment surrounding them, including complex molecules which can be bigger than the tool itself (!), is not well understood. The tools we are interested in are crystalline semiconductor particles so small that one could fit more than ten thousands of them on the edge of a piece of paper. These nanometer-sized particles are called quantum dots to underline that their behaviour is governed by the laws of quantum mechanics. In this sense, they behave like artificial atoms for which we can engineer the properties eventually leading to entirely new materials. However compared to the natural atoms, we don't have the equivalent of a periodic table of elements to guide us on how the quantum dots interact together and with other molecules. To probe this interaction, we will use the light emitted by the quantum dots. The color (wavelength) of this light is one of the properties we can engineer simply by changing the quantum dot size. The emitted light also blink on and off randomly when the quantum dots are synthesized and kept in a liquid, but these fluctuations interestingly do not occur when the quantum dots are grown in a semiconductor solid. With the light intensity and wavelength, the statistics of this blinking constitute a third parameter to investigate the collective interaction dynamics of the atoms inside and outside the quantum dots. Three types of quantum dot samples will be probed through their emitted light: one where the quantum dots are on a semiconductor surface, one where the quantum dots will be buried just below the semiconductor surface within range of quantum interactions and one where the quantum dots are embedded in conductive polymers. With this last sample, we will be able to give energy to the quantum dots by passing current through the conductive polymer device whereas the other samples receive energy via excitation with a laser. Research on quantum dots in this organic polymer device will contribute to the development of a whole new generation of transparent, flexible, light-weight and even printable technologies from solar cells to light emitting devices.

在蓬勃发展的纳米技术领域，我们仍处于小规模工具开发的起步阶段。这些工具与周围环境（包括可能比工具本身更大的复杂分子（！））的相互作用尚不清楚。我们感兴趣的工具是晶体半导体颗粒，非常小，可以在一张纸的边缘容纳数万个以上的颗粒。这些纳米尺寸的粒子被称为量子点，以强调它们的行为受量子力学定律支配。从这个意义上说，它们的行为就像人造原子，我们可以为其设计其特性，最终产生全新的材料。然而，与自然原子相比，我们没有相当于元素周期表的元素来指导我们量子点如何相互作用以及与其他分子如何相互作用。为了探测这种相互作用，我们将使用量子点发出的光。这种光的颜色（波长）是我们可以通过改变量子点尺寸来设计的属性之一。当量子点被合成并保存在液体中时，发射的光也会随机闪烁，但有趣的是，当量子点在半导体固体中生长时，这些波动不会发生。与光强度和波长一起，这种闪烁的统计数据构成了第三个参数，用于研究量子点内外原子的集体相互作用动力学。将通过发射光探测三种类型的量子点样品：一种是量子点位于半导体表面上，一种是量子点将埋在半导体表面正下方的量子相互作用范围内，另一种是量子点嵌入导电聚合物中。对于最后一个样品，我们将能够通过使电流流过导电聚合物装置来向量子点提供能量，而其他样品则通过激光激发来接收能量。对这种有机聚合物器件中量子点的研究将有助于开发从太阳能电池到发光器件的全新一代透明、柔性、轻质甚至可印刷技术。