No abstract

The synthesis of poly(methyl methacrylate) (PMMA) exhibiting one fluorescent dye (Texas Red) and one methyl disulfide end group is described. It is shown that the latter end group enabled the exchange of both oleic amine on gold nanoparticles (AuNP) and of oleic acid on CdSe/ZnS quantum dots (QD), allowing for a phase transfer of both types of nanoparticles (NP) from hexane into dimethylformamide due to the solubility provided by the PMMA chains. For AuNP, a fluorescence quenching of the dye was found due to fluorescence resonance energy transfer (FRET) from the dye to the AuNP, while QDs caused a fluorescence enhancement by FRET from the QD to the attached dyes. Due to the hetero-telechelic geometry of the polymer, the separation between NP and dye is governed by the end-to-end distance of the polymer.

The nanoscale positioning of QD donors and dye acceptors enables an effective control of the fluorescence resonance energy transfer from QDs to dyes in a single-layered film of diblock copolymer micelles.

Metal nanocrystals synthesized with a micellar template were applied for three-dimensional vertical floating gate memory devices. Using a highly ordered micellar template formed with a diblock copolymer, we produced cobalt ͑Co͒ nanocrystals with a uniform size and spatial distribution on a planar surface and a sidewall surface. The hydrogen annealing effects were investigated in terms of memory performance. The fabricated vertical floating gate memory with Co nanocrystals annealed with hydrogen showed a memory window with a voltage greater than 1 V and a retention time characteristic that preserves more than 60% of the initial charge after ten years.

With a simple and conformal metal nanocrystal dipping of synthesized micelles, nonvolatile memory characteristics originating from a metallic cobalt (Co) core nanocrystal (NC) surrounded by a Co-oxide shell are investigated in this study. From transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS), it was confirmed that Co-oxide was made by oxygen plasma for polymer oxidation and that metallic Co wrapped with a Co-oxide shell was made by hydrogen annealing in order to reduce the Co-oxide. Energy band diagrams considering the extent of the coexistent metallic Co/Co-oxide were also analyzed in terms of how they correspond to each program/erase/retention case. These cases were verified by electrically measured data. These results can provide a guideline for the design and optimization of metal NC embedded memory.