Congratulations to Professor Maxx Arguilla on receiving a NSF CAREER award. The award is for his group's research that aims to develop ultrathin optical and electronic materials entitled "CAREER: Anisotropy-Directed Synthesis of Optically Active 1D van der Waals Nanocrystals and Development of Multiscale Solid State Chemistry Educational Activities".
Read the abstracts for the proposal below:
The 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.
The 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.