Real-time imaging of light-induced transformations in phase-change materials

相变材料中光诱导转变的实时成像

• 批准号: RGPIN-2021-03797
• 负责人: Beyerlein, Kenneth
• 金额: $ 2.11万
• 依托单位: Institut national de la recherche scientifique
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=752614
• 关键词: Real; time; imaging; light; induced

In this digital age, we rely on computers in many aspects of our daily life. Their performance not only influences how we communicate and work, but also the efficacy of our banks and medical care. It is then in the best interest of Canada to invest in their development to maintain a strategic advantage in this sector. This Discovery Grant (DG) contributes to this goal by studying the dynamics of phase-change materials that are important for computer memory devices and have the potential to enable more efficient computer architectures. Today's computers follow a von Neumann architecture, where data must be moved between physically separate processing and memory units. As the speed of processors has outpaced that of memory, the bottle neck is now the time it takes to shuttle data back and forth. This can be overcome by performing both actions in a single device, referred to as in-memory computing. However, practical realization of such devices requires materials that can both rapidly and irreversibly switch between states for combined fast processing and non-volatile memory functionality. Phase-change materials based on chalcogenide alloys have been largely investigated for this purpose, and are already used in the computer industry for optical data storage - the composition Ge2Sb2Te5 is used in DVDs, and Ge8Sb2Te11 is used in Blue-ray disks. Data can be written in these devices using a laser or electric current to locally heat a small region, and switch it between an insulating amorphous glass phase and a conductive crystalline phase. The resultant phase is determined by the amount of heat absorbed in the process that is controlled by the incident laser power or electric current. However, the maximum data writing speed is currently limited by the amorphous to crystalline phase transformation time. It is then the goal of this DG to explore ways to increase this transformation speed and track the corresponding material structural evolution in real time using the dynamic transmission electron microscope (DTEM) at INRS. This unique microscope has the capability to capture a sequence of nanosecond images of irreversible transformations with near-atomic resolution. Specifically, this DG will address critical outstanding questions about the crystallization of phase-change materials by exploring the following research directives: (1) imaging rapidly cooled transformations, (2) tracking precursors in the amorphous phase, and (3) ultra-localized nano-plasmonic heating. This research is expected to lead to a deeper understanding of this technologically important transformation, which can impact the future design of computers. Furthermore, the expertise gained by highly qualified personnel trained in this program is widely transferable to other sectors of the Canadian technology industry.

在这个数字时代，我们在日常生活的许多方面都依靠计算机。他们的绩效不仅会影响我们的交流和工作方式，还影响了银行和医疗服务的功效。那么，加拿大的最大利益是要投资于他们的发展，以维持该领域的战略优势。这项发现赠款（DG）通过研究对计算机内存设备很重要的相变材料的动态来促进这一目标，并有可能使更有效的计算机体系结构。当今的计算机遵循von Neumann架构，必须在物理分开的处理和内存单元之间移动数据。随着处理器的速度超过了内存的速度，现在瓶颈是来回驶入数据所需的时间。可以通过在单个设备中执行这两个操作（称为内存计算）来克服这一点。但是，此类设备的实际实现需要材料，这些材料既可以在状态之间快速和不可逆地切换，以进行快速处理和非易失性存储功能。基于硫元化合物合金的相位变化材料已在此目的很大程度上研究，并且已经在计算机行业中用于光学数据存储 - DVD中使用了组合GE2SB2TE5，GE8SB2TE11用于蓝射线磁盘中。数据可以使用激光或电流在这些设备中编写，以局部加热一个小区域，并在绝缘无定形玻璃相和导电晶相之间切换。结果阶段取决于由入射激光功率或电流控制的过程中吸收的热量。但是，最大数据编写速度当前受到晶体相变时间的无定形限制。 然后，该DG的目的是探索使用动态传输电子显微镜（DTEM）在INRS上实时提高这种转换速度并实时跟踪相应材料结构演变的方法。这种独特的显微镜具有捕获一系列具有近原子分辨率的不可逆变换的纳秒图像。具体而言，该DG将通过探索以下研究指令来解决有关相变材料结晶的关键问题：（1）成像快速冷却的转换，（2）在无定形相中跟踪前体，以及（3）超定位的纳米质量加热。预计这项研究将导致对这一技术上重要的转变有更深入的了解，这可能会影响计算机的未来设计。此外，在该计划中培训的高素质人员获得的专业知识可以广泛转移到加拿大技术行业的其他领域。