CAREER: Anisotropy-Directed Synthesis of Optically Active 1D van der Waals Nanocrystals and Development of Multiscale Solid State Chemistry Educational Activities

职业：光学活性一维范德华纳米晶体的各向异性定向合成和多尺度固态化学教育活动的发展

• 批准号: 2340918
• 负责人: Maxx Arguilla
• 金额: $ 72.68万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-02-01 至 2029-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2340918&HistoricalAwards=false
• 关键词: CAREER; Anisotropy; Directed; Synthesis; Optically

NON-TECHNICAL ABSTRACTThe next generation of faster, more efficient, and densified functional devices require solid state building blocks that have sizes that approach the atomic scale. Inorganic one-dimensional (1D) solids that crystallize as fiber-like bundles bearing single chains with thicknesses less than a nanometer gained recent attention due to their high degrees of conductivity and strong absorption characteristics that make them suitable for energy-efficient electronic and photonic devices. However, while promising, there is meager understanding of the synthetic methodologies to control the nanoscale morphology, size, and physical properties of these 1D solids. With this CAREER award, supported by the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, the principal investigator and his research group will elucidate the chemical cues that precisely direct and influence the crystallization of these 1D inorganic fibers into nanoscale crystals with various sizes and dimensionalities. The resulting array of dimensionally resolved nanostructures is used to systematically establish how the optical properties evolve from the bulk down to ultrathin nanostructures. It is anticipated that these strategies are translatable to several classes solids that display 1D fiber-like motif, poised as ultrathin building blocks in quantum computing, microelectronics, energy, and sensing technologies. The unique nature of these materials which bridge bulk and nanoscale solids presents an ideal platform to train budding scientists. Students across multiple levels are introduced to synthetic and characterization techniques, as well as the practical applications, which involve solid state materials through complementary hands-on demonstration, summer bootcamp, and mentorship activities.TECHNICAL ABSTRACTThe discovery of complex phenomena and strongly correlated behavior in the solid state has relied on the precise sculpting of solids into stable low-dimensional crystals approaching the atomic limit. Whereas 2D van der Waals (vdW) solids are well studied, little is known about the chemistry and physics of the more confined 1D/quasi-1D (q-1D) vdW counterparts. In these length scales and dimensionalities, unique physical properties arising from finite size effects like ballistic electrical transport, size-dependent optical resonance modes, long carrier lifetimes, and 1D excitonics become realizable. With this CAREER award, supported by the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, the principal investigator and his research group addresses the chemical knowledge gap by elucidating the chemical cues that, first, direct the assembly of 1D/q-1D vdW chain sub-units into well-defined nanostructures (as nanowire, nanoribbon, or nanosheet) and, second, control and alter the electronic band structures and photophysical properties of the resulting nanocrystals. The overarching hypothesis is that the control over the degree of anisotropic inter-chain vdW interactions enables the precise nanocrystalline dimensional resolution which, in turn, could improve the optoelectronic properties of bottom-up grown 1D/q-1D vdW nanostructures. The specific objectives, which involve pnictogen- and chalcogen-based 1D/q-1D vdW crystals, are: (1) establish the intrinsic chemical interactions governing anisotropic bonding, structure, and nanoscale growth habits from vapor phase precursors; (2) identify extrinsically directed growth pathways to control morphologies and sizes in 1D/q-1D vdW nanostructures through engineered nucleation, flux control, and catalyzed growth routes in a chemical vapor deposition system; and (3) mechanistically elucidate vapor phase intra- and inter-chain growth pathways that lead to dimensionally resolved 1D/q-1D vdW nanocrystals with modulable photophysical properties via hierarchical assembly and heterostructuring. The unique structure and properties of these low-dimensional solids facilitate the development of educational activities introduce the chemistry, properties, and applications of both bulk and nanoscale solid state materials to students across various levels, including a solid state and nano-chemistry bootcamp and mentoring program.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.

非技术摘要下一代更快、更高效和更致密的功能器件需要具有接近原子尺度的尺寸的固态构建块。无机一维（1D）固体结晶为纤维状束，带有厚度小于1纳米的单链，由于其高度的导电性和强吸收特性，使其适用于节能电子和光子器件，因此最近受到关注。然而，虽然有希望，有微薄的理解的合成方法来控制这些一维固体的纳米级形态，尺寸和物理性质。在NSF材料研究部门的固态和材料化学项目的支持下，该职业奖的主要研究者和他的研究小组将阐明化学线索，这些化学线索精确地指导和影响这些一维无机纤维结晶成具有各种尺寸和维度的纳米晶体。由此产生的阵列的尺寸分辨纳米结构被用来系统地建立光学性质如何演变从散装下到纳米结构。预计这些策略可转化为显示1D纤维状基序的几类固体，作为量子计算，微电子，能源和传感技术中的可编程构建块。这些材料的独特性质，桥梁散装和纳米级固体提供了一个理想的平台，以培养崭露头角的科学家。学生在多个级别的介绍合成和表征技术，以及实际应用，其中涉及固态材料通过互补的动手演示，夏令营，和mentorship activities.TECHNICAL ABSTRACTThe发现复杂的现象和强烈相关的行为在固态依赖于固体的精确雕刻成稳定的低维晶体接近原子极限。虽然二维货车德瓦耳斯（vdW）固体研究得很好，很少有人知道更多的限制一维/准一维（q-1D）vdW对应的化学和物理。在这些长度尺度和维度中，由有限尺寸效应产生的独特物理性质，如弹道电输运，尺寸依赖的光学共振模式，长载流子寿命和1D激子变得可实现。在NSF材料研究部门的固态和材料化学项目的支持下，首席研究员和他的研究小组通过阐明化学线索来解决化学知识差距，首先，指导1D/q-1D vdW链亚单元组装成明确的纳米结构纳米晶体可以是纳米晶体（作为纳米线、纳米晶体或纳米片），并且第二，控制和改变所得纳米晶体的电子能带结构和电子物理性质。首要假设是，对各向异性链间vdW相互作用程度的控制能够实现精确的纳米晶尺寸分辨率，这反过来又可以改善自下而上生长的1D/q-1D vdW纳米结构的光电性能。具体目标包括：（1）从气相前体建立控制各向异性键合、结构和纳米级生长习惯的内在化学相互作用;（2）通过工程化成核，通量控制，和化学气相沉积系统中的催化生长途径;和（3）机械地阐明气相链内和链间生长途径，其通过分级组装和异质结构化导致具有可调制的物理化学性质的尺寸分辨的1D/q-1D vdW纳米晶体。这些低维固体的独特结构和性质促进了教育活动的发展，向各个层次的学生介绍了块状和纳米级固态材料的化学，性质和应用，包括固态和纳米-该奖项反映了NSF的法定使命，并通过使用基金会的知识产权进行评估，被认为值得支持。优点和更广泛的影响审查标准。