Collaborative Research: Studies of Explosive Crystallization

国家科学基金提案号：cts -0431431 cts -0431409首席研究员：Benard J. Matkowsky and Alexander A. golovincosta as grigoropoulos合作单位：西北大学加州大学伯克利分校提案标题：合作研究：摘要非晶材料的爆炸结晶是一种引人入胜的现象，二十多年来一直受到工程师、物理学家、材料学家等各界人士的广泛关注。它表现为固体材料从亚稳态非晶态到稳定晶态的热激活，高度放热的相变，以自传播结晶锋的形式发生。前方传播可以由机械产生的局部热上升或激光束触发。激光触发非晶半导体薄膜的爆炸结晶是一种广泛应用的生产绝缘体上硅结构的现代技术，在太阳能电池或红外探测器等各种光伏器件中具有广泛的应用，并且在面板显示等方面具有低成本，低功耗的特点。该项目的目标是在西北大学的理论小组和伯克利大学的实验小组之间发起和发展富有成效的合作，对以前没有研究过的爆炸结晶的几个重要方面进行系统的理论和实验研究。合作将集中在数学建模和实验研究的非线性动力学的不稳定性表现出爆炸结晶前沿和由此产生的微观结构。具体来说，我们打算研究几种不同锋面传播模式下爆炸结晶锋面的稳定性和非线性动力学，以及合金中的爆炸结晶和掺杂剂对结晶动力学的影响。从基本观点来看，所提出的研究的意义在于阐明了几种模式下爆炸结晶前沿的不稳定性和非线性动力学等重要影响，这些模式提供了远离热力学平衡的系统中复杂非线性行为的例子。从工艺的角度来看，这些结果将增强我们对非晶薄膜爆炸结晶的现代工艺过程的理解。建立的合作将使我们在未来的联合研究中更进一步，对爆炸结晶材料的微观结构进行更详细的研究，这是控制和优化过程的必要前提。拟议研究的更广泛影响在于它的跨学科性质，它对科学家和工程师都很重要。它还将为培养研究生在未来合作研究阶段的良好基础，为他们提供独特的机会，参与工程、应用物理和应用数学前沿的重要研究，结合理论和实验组成部分。这项研究是由数学和物理科学理事会的数学科学司和工程理事会的化学和运输系统司共同资助的。基金来自数学科学：与科学和工程项目接口的创新，公告NSF 04-538。

National Science FoundationProposal Number: CTS-0431431CTS-0431409Principal Investigator: Benard J. Matkowsky and Alexander A. GolovinCostas GrigoropoulosAffiliation: Northwestern UniversityUniversity of California-BerkeleyProposal Title: Collaborative Research: Studies of explosive crystallizationAbstractExplosive crystallization of amorphous materials is a fascinating phenomenon that has attracted much attention from engineers, physicists, materials scientists and others for over two decades. It manifests itself as a thermally activated, highly exothermic phase transition of a solid material from a metastable amorphous state to a stable crystalline state, that occurs in the form of a self-propagating crystallization front. The front propagation can be triggered by a local heat rise produced mechanically, or by a laser beam. The laser-beam-triggered explosive crystallization of amorphous semiconductor films is a widely used modern technology for producing silicon-on-insulator structures that have many applications in various photovoltaic devices like solar cells or infrared detectors, low-cost, low-power consuming at panel displays, etc. The objective of the proposed project is to initiate and develop a fruitful collaboration between the theoretical group at Northwestern and the experimental group at Berkeley, to carry out systematic theoretical and experimental investigations of several important aspects of explosive crystallization that have not been previously studied. The collaboration will focus on mathematical modeling and experimental studies of nonlineardynamics of instabilities exhibited by explosive crystallization fronts and the resulting microstructures. Specifically, we propose to investigate the stability and nonlinear dynamics of explosive crystallization fronts in several different modes of frontal propagation, as well as explosive crystallization in alloys and the effect of dopants on the crystallization dynamics. From the fundamental point of view, the significance of the proposed research is in elucidating such important effects as the instabilities and nonlinear dynamics of explosive crystallization fronts in several modes that provide examples of complex nonlinear behavior in systems far from thermodynamic equilibrium.From the technological point of view, the results will enhance our understanding of the modern technological process of explosive crystallization in thin amorphous films. The established collaboration will allow us to move further in our future joint research to more detailed investigations of microstructure in explosively crystallizing materials which is a necessary prerequisite to control and optimization of the process. The broader impact of the proposed research lies in its interdisciplinary nature, its importance for bothscientists and engineers. It will also create a sound basis for training graduate students in future stages of the collaborative research that will provide them with the unique opportunity to participate in important research at the cutting edge of engineering, applied physics and applied mathematics, combining both theoretical and experimental components.This research has been funded jointly by the Division of Mathematical Sciences in the Mathematics and Physical Sciences Directorate and the Division of Chemical and Transport Systems in the Engineering Directorate. Funding is from the Mathematical Sciences: Innovations at the Interface with the Sciences and Engineering Program, Announcement NSF 04-538.