We report the transport and trapping behavior of 100 and 500 nm diameter nanospheres in a plasmon-enhanced two-dimensional optical lattice. An optical potential is created by a two-dimensional square lattice of gold nanostructures, illuminated by a Gaussian beam to excite plasmon resonance. The nanoparticles can be guided, trapped, and arranged using this optical potential. Stacking of 500 nm nanospheres into a predominantly hexagonal closed pack crystalline structure under such a potential is also reported.

Despite the widespread interest in the examinations of catalytic and facet-dependent properties of Cu2O crystals, it was still difficult to grow ultrasmall Cu2O cubes and octahedra with tunable sizes at a large scale. In this work, CuSO4, NaOH, and sodium ascorbate of varying volumes were added to an aqueous sodium dodecyl sulfate (SDS) solution to generate Cu2O nanocubes with average edge lengths of 16, 25, 29, 36, 51, 63, 72, and 86 nm in just 10 min. Another series of Cu2O cubes with wide size tunability in the range of 27–200 nm is accomplished by simply adjusting the NaOH volume. Similar reaction conditions can also be used to make a large quantity of Cu2O octahedra with opposite corner distances of just 34, 41, and 49 nm. Remarkably, production of these small Cu2O cubes and octahedra is scalable to 500 mL in one reaction. UV–vis absorption and photoluminescence spectra establish their size and facet-dependent optical properties, and a modified band diagram of Cu2O is presented. Recognizing Cu2O nanocrystal shape evolution is possible by changing the cell potential, we have proven this concept to yield cubic to truncated octahedral and octahedral structures by varying the CuSO4 volume. Finally, the tiny Cu2O cubes and octahedra were pseudomorphically converted to Cu cubes and octahedra via the introduction of ammonia borane, so these small copper polyhedra become readily accessible for diverse catalytic and plasmonic applications.

Electrical conductivity properties of Ge {100}, {110}, {111}, and {211} facets have been measured by breaking Ge (100) and (111) wafers to expose {110} and {211} surfaces and contacting the different facets with tungsten probes. Ge {111} and {211} faces are far more conductive than the already conductive Ge {100} and {110} faces, matching with recent density functional theory (DFT) predictions. Asymmetric I–V curves resembling those of p‐n junctions have been collected for the {110}/{111} and {110}/{211} facet combinations. The current‐rectifying effects stem from different degrees of surface band bending for the highly and less conductive faces and the direction of current flow. This work demonstrates that germanium wafers also possess facet‐dependent electrical conductivity responses that can be utilized in the fabrication of novel fin field‐effect transistors (finFET).

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CsPbBr3 rhombic dodecahedra, octahedra, and nanocubes have been synthesized using typical reagents but by adjusting the amounts of organic capping molecules used and the reaction temperature. Although some Cs4PbBr6 has...