Collaborative Research: Directed Templating of Semiconductor Nanocrystals Through Laser Melting

合作研究：通过激光熔化实现半导体纳米晶体的定向模板化

• 批准号: 1363313
• 负责人: Heng Pan
• 金额: $ 11万
• 依托单位: Missouri University of Science and Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1363313&HistoricalAwards=false
• 关键词: Collaborative; Research; Directed; Templating; Semiconductor

Many applications in photonic and electronic devices require high quality semiconductor crystal growth on supporting materials that do not intrinsically promote, nor are compatible with current manufacturing processes. The essential, but still challenging step is the deliberate templating of nanocrystals with the desired size, orientation and placement accuracy on such substrates. This award supports fundamental research to acquire knowledge for achieving nanoscale control of nucleation and crystal growth processes. The research will open the way to the fabrication of thin crystalline domains on inexpensive and abundant substrates as well to the fabrication of quantum nanodevices. Applications include thin film transistors for advanced displays, high performance thin film solar cells, three-dimensional electronic devices and quantum computers. The research will benefit the U.S. industry, economy and society. The coupled experimental and computational methodology and state of the art nanofabrication will provide new opportunities for undergraduate and graduate students and in particular underrepresented minorities to have research experiences and state-of-the-art training in nanoscience and engineering, consequently positively impacting engineering education.Nanocrystal seeds with highly uniform size and orientations will be manufactured by laser crystallization in confined nanodomains. The research team will achieve fundamental understanding of laser crystallization in nanodomains by combining direct imaging via in situ Transmission Electron Microscopy (TEM) with detailed multi-scale computational modeling and molecular dynamics (MD) simulations. This uniquely integrated research approach will enable engineering of the nanoconfinement geometry and the imposed transient laser protocol parameters for reliable generation of well-controlled seeding nanocrystals. State of the art focused ion beam (FIB) processing and laser interference lithography will be utilized to define nanocavities with minimum diameter 10 nm wherein amorphous semiconductors (Si, Ge) will be deposited. Nano-cavities on large area will be fabricated by nanoimprinting with FIB fabricated molds. Pulsed laser radiation in combination with modulated background heating will be utilized to convert the amorphous deposits into nanocrystals with deliberately engineered size and crystallographic orientation. Such generated localized crystals can serve as crystallization seeds, overcoming uncertainty associated to un-engineered spontaneous nucleation. Molecular Dynamics (MD) simulation will be performed at the same length scale to provide fundamental understanding of heat transfer, nucleation mechanism, crystal growth and defect evolution in nano-confined domains. Finally, a seeded crystallization process will enable controlled growth of a large area monocrystalline thin layer on epitaxially non-participating substrates.

光子和电子设备中的许多应用都需要高质量的半导体晶体生长在没有内在促进的支持材料上，也不与当前的制造工艺兼容。必不可少的但仍然具有挑战性的步骤是，在此类底物上具有所需尺寸，方向和放置精度的纳米晶体的故意模板。该奖项支持基础研究，以获取知识，以实现纳米级的核能控制和晶体生长过程。这项研究将为廉价且丰富的底物上的薄晶域制造开辟道路，并制造量子纳米用途的制造。应用包括用于高级显示器的薄膜晶体管，高性能薄膜太阳能电池，三维电子设备和量子计算机。这项研究将使美国工业，经济和社会受益。实验和计算方法论以及艺术纳米制作的状态将为本科生和研究生，尤其是人为少数群体提供新的机会，以便在纳米科学和工程中接受研究经验和最先进的培训，从而对工程进行积极影响，从而通过高度统一的大小和方面进行了综合式构造。研究团队将通过将直接成像通过原位传输电子显微镜（TEM）与详细的多尺度计算建模和分子动力学（MD）模拟相结合，从而实现对纳米域激光结晶的基本理解。这种独特的整合研究方法将使纳米芬的几何形状和施加的瞬态激光协议参数能够进行工程，以可靠地生成良好控制的良好的播种纳米晶体。将使用焦点的离子束（FIB）加工和激光干扰光刻来定义最小直径为10 nm的纳米腔，其中无定形半导体（SI，GE）被沉积。大面积的纳米腔将通过使用FIB制造的模具来制造纳米印刷。脉冲激光辐射与调制背景加热结合使用，将其用于具有故意设计的大小和晶体学取向的纳米晶体。这种产生的局部晶体可以用作结晶种子，克服与非设计的自发成核相关的不确定性。分子动力学（MD）模拟将以相同的长度尺度进行，以提供对纳米固定结构域中传热，成核机制，晶体生长和缺陷演化的基本理解。最后，种子结晶过程将使大面积的单晶层薄层在外上一根非参与底物上受控生长。