Theoretical Studies on Electronic Spin Flipping and Relevant Phenomena in Optoelectronics

光电子学中电子自旋翻转及相关现象的理论研究

• 批准号: RGPIN-2016-06276
• 负责人: Zeng, Tao
• 金额: $ 2.55万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=616203
• 关键词: Theoretical; Studies; Electronic; Spin; Flipping

Theoretical Studies on Electronic Spin Flipping and Relevant Phenomena in Optoelectronics Electrons have an intrinsic spin that can take two quantized values, just like the two faces of a coin. Flipping electronic spin can drastically change the reactivity of a molecule and lead to unexpected results. Electronic spin flipping occurs in many reactions involving oxygen, especially in the realms of biochemistry and combustion chemistry. For instance, it occurs in the oxidation reaction in breathing. We have all adapted to the spin-flipping rate that was chosen by nature. If suddenly the flipping of the oxygen electronic spin were slower, we would all have oxygen deprivation symptoms. If it were too fast, we would all start to burn and become the more stable carbon dioxide and water. Given the importance of electronic spin flipping in chemistry, we endeavor to develop accurate and efficient theoretical chemistry methods to simulate the flipping. Compared to other methods that have been developed, our methods will include the important nuclear quantum effects and will be more efficient, and hence more applicable to large, realistic systems. The methods will be applied to investigate interesting flipping processes and explain/predict phenomena. Our research program has applications that are related to energy science and sustainable chemistry. We will not be able to rely on fossil fuel exclusively. Solar energy is a clean alternative, and certain types of organic materials can convert solar energy to electricity. Organic materials are attractive because they feature numerous advantages such as low cost, high production, and mechanical flexibility. However, organic solar cells are not as widely used today as their inorganic counterparts and one reason is their relatively low light-to-electricity conversion efficiency. We aim at designing organic molecules that can undergo intramolecular singlet fission, a process that can potentially double the conversion efficiency. Organic light-emitting diodes take the opposite process of organic solar cells. They convert electricity to light and feature similar advantages, but also low conversion efficiency. We will employ theoretical chemistry methods to design organic molecules that undergo thermally activated delayed fluorescence, a process that has been shown to significantly increase the energy conversion efficiency from ~5% to ~20%. We are especially interested in designing small molecules for organic solar cells and organic light-emitting diodes, since they are lightweight and will eventually lead to transportation-friendly devices. This research program has a significant impact in making energy efficient devices. It will eventually benefit Canada’s energy-related industry. It is a combination of theoretical development and applied studies, and therefore provides an opportunity for multidisciplinary personnel training.

光电子学中电子自旋翻转及相关现象的理论研究 电子有一个内在的自旋，可以取两个量子化值，就像硬币的两面一样。翻转电子自旋可以极大地改变分子的反应性，并导致意想不到的结果。电子自旋翻转发生在许多涉及氧气的反应中，特别是在生物化学和燃烧化学领域。例如，它发生在呼吸的氧化反应中。我们都已经适应了自然选择的自旋翻转速率。如果氧电子自旋的翻转突然变慢，我们都会出现缺氧症状。如果它太快，我们都会开始燃烧，变成更稳定的二氧化碳和水。鉴于电子自旋翻转在化学中的重要性，我们奋进发展准确有效的理论化学方法来模拟翻转。与已经开发的其他方法相比，我们的方法将包括重要的核量子效应，并且将更有效，因此更适用于大型，现实的系统。这些方法将被应用于研究有趣的翻转过程和解释/预测现象。 我们的研究项目具有与能源科学和可持续化学相关的应用。我们不能完全依赖化石燃料。太阳能是一种清洁的替代能源，某些类型的有机材料可以将太阳能转化为电力。有机材料是有吸引力的，因为它们具有许多优点，如低成本，高产量和机械灵活性。然而，有机太阳能电池如今的应用并不像无机太阳能电池那样广泛，原因之一是它们的光电转换效率相对较低。我们的目标是设计可以进行分子内单线态裂变的有机分子，这一过程可能使转换效率加倍。有机发光二极管采用与有机太阳能电池相反的工艺。它们将电转换为光，具有类似的优点，但转换效率低。我们将采用理论化学方法来设计经历热激活延迟荧光的有机分子，这一过程已被证明可以显着提高能量转换效率，从~5%到~ 20%。我们对设计用于有机太阳能电池和有机发光二极管的小分子特别感兴趣，因为它们重量轻，最终将导致运输友好型设备。 这项研究计划在制造节能设备方面具有重大影响。这将最终有利于加拿大的能源相关产业。它是理论发展和应用研究的结合，因此为多学科人才培养提供了机会。