Quasi-Random Multimetallic Nanoparticle Arrays

Abstract

This paper describes a nanofabrication procedure that can generate multiscale substrates with quasi-random microregions of nanoparticle arrays having different periodicities and metals. We combine cycles of large-area nanoparticle array fabrication with solvent-assisted wrinkle lithography to mask and etch quasi-random areas of prefabricated nanoparticles to control the fill factors of the arrays. The approach is highly flexible, and parameters, including nanoparticle size and material, array geometry, and fill factor, can be tailored independently. Multimetallic nanoparticle arrays can support surface lattice resonances at fill factors as low as 20% and can function as nanoscale cavities for lasing action with as few as 10% of the nanoparticles in an array. We demonstrated that multimetallic nanoparticle substrates that combine two or three arrays with different periodicities can exhibit lasing responses over visible and near-infrared wavelengths. Our work showcases the robust optical responses of multimetallic and periodic devices for broadband light manipulation.

Dual-Interface-Mediated Tunable Self-Assembly of 2D Periodic Nanostructures and DNA-Driven Reconstructions

“…At present, most strategies leverage weak intermolecular interactions between NPs without long-range selectivity, thus limiting the ability to access the long-range periodic structures of NPs. − Alternatively, combinations of top-down and bottom-up techniques have been reported to introduce NP-template interfacial interactions, which can confine the growth or assembly of nanostructures on a template surface. For instance, various functional templates have been obtained through techniques including electron beam etching, colloidal lithography, and nanoimprinting, etc. − Chemical or physical modification of the patterned templates allows for the deterministic self-assembly of NPs, yielding two-dimensional (2D) periodic arrays of NPs over large areas. Nevertheless, flexible control of the various complex interfacial interactions in these approaches, which is pivotal to the regioselective self-assembly of NPs on a surface, is still difficult.…”