RII Track-4: Low-temperature Laser Sintering and Melting of Semiconductors Through Selective Excitation of Soft Phonons

RII Track-4：通过软声子的选择性激发实现半导体的低温激光烧结和熔化

• 批准号: 2033424
• 负责人: Yan Wang
• 金额: $ 27.45万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2033424&HistoricalAwards=false
• 关键词: RII; Track; Low; temperature; Laser

Sintering and melting has become an integral processing step in consolidating semiconductor powders into compact engineering components. Laser sintering and melting stands out among processing options due to its high throughput, controllability, and natural ability to 3D print components. However, conventional laser processes typically heat materials to such high temperatures that the target region fully or partially melts, which can damage the sintered region and its surroundings due to overheating. This project aims to melt and sinter semiconductors at a reduced temperature by exploiting ultrafast laser-material interactions at the electronic and atomic levels. Complementary experimental-computational studies leveraging the advanced laser systems at the University of Nebraska, Lincoln (UNL) will be conducted to understand the dynamics of atoms in semiconductors under laser irradiation. Successful completion of this project will improve 3D printing technologies for various modern applications that rely on nanocrystalline semiconductors, such as solar cells and thermoelectric materials. This project will improve laser manufacturing education at the University of Nevada, Reno (UNR) through the development of innovative K-12 programs and undergraduate/graduate-level curricula. The ultrafast laser manufacturing techniques acquired through this project will also enhance Nevada and UNR’s competitiveness in additive manufacturing. The goal of this project is to achieve laser sintering and melting of semiconductors at significantly reduced temperatures compared to those in conventional laser processes, which will greatly reduce the adverse thermal effects (e.g., unwanted grain growth that degrades material properties) caused by prolonged high material temperature. To achieve this goal, three specific objectives will be pursued with complementary computational-experimental techniques: 1) identify the patterns of atomic motions that can effectively and efficiently trigger the melting of semiconductors using atomistic modeling; 2) elucidate the melting dynamics using quantum-mechanical calculations; and 3) demonstrate the proposed process using a dual-laser system that combines the strengths of the advanced ultrafast laser systems and the tunable-wavelength continuous laser systems at UNL. The successful completion of this project will lead to a low-temperature laser sintering and melting process with improved ability to control the microstructures and properties of 3D printed semiconductors, enabling 3D printing of high-quality thermoelectric modules, solar cells, electronic devices, etc. The acquired expertise in ultrafast laser processing, developed K-12 education programs on advanced manufacturing, and strengthened collaboration with an established laser manufacturing researcher from UNL will greatly strengthen the competitiveness of Nevada, UNR, and the principal investigator in the field of additive manufacturing and related applications like energy and electronics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

烧结和熔化已成为将半导体粉末固结成紧凑的工程部件的不可或缺的加工步骤。激光烧结和熔化由于其高吞吐量、可控性和3D打印组件的自然能力而在加工选项中脱颖而出。然而，传统的激光工艺通常将材料加热到目标区域完全或部分熔化的高温，这可能由于过热而损坏烧结区域及其周围环境。该项目旨在通过利用电子和原子水平上的超快激光-材料相互作用，在降低的温度下熔化和烧结半导体。将利用内布拉斯加大学林肯分校（UNL）的先进激光系统进行补充实验-计算研究，以了解激光照射下半导体中原子的动力学。该项目的成功完成将为依赖纳米晶半导体的各种现代应用（如太阳能电池和热电材料）改进3D打印技术。该项目将通过开发创新的K-12课程和本科/研究生课程，改善内华达州里诺大学（UNR）的激光制造教育。通过该项目获得的超快激光制造技术也将增强内华达州和UNR在增材制造领域的竞争力。该项目的目标是在与传统激光工艺相比显著降低的温度下实现半导体的激光烧结和熔化，这将大大减少不利的热效应（例如，降低材料性能的不希望的晶粒生长）。为了实现这一目标，我们将采用计算-实验相结合的方法，实现三个具体的目标：1）利用原子模型确定能够有效地触发半导体熔化的原子运动模式; 2）利用量子力学计算阐明熔化动力学;以及3）使用结合了UNL先进的超快激光系统和可调谐波长连续激光系统的优点的双激光系统来演示所提出的过程。该项目的成功完成将带来低温激光烧结和熔化工艺，提高控制3D打印半导体微观结构和性能的能力，实现高质量热电模块，太阳能电池，电子设备等的3D打印。并加强与UNL的激光制造研究人员的合作，将大大加强内华达州，UNR，以及增材制造及能源和电子等相关应用领域的首席研究员。该奖项反映了NSF的法定使命，并通过使用基金会的学术价值和更广泛的影响审查标准。