We present a simple nonlithographic approach to arrange luminescent CdSe and core/shell CdSe/ZnS nanocrystals into large area periodic lateral patterns. Selective deposition onto organic channel-like templates fabricated by the Langmuir−Blodgett technique is achieved by anisotropic dewetting of the nanocrystal carrier solvent. Lateral patterning over large areas of several square centimeters is demonstrated on a time scale of a few minutes. The filling fraction of nanocrystals within the deposited channels is controlled by their concentration in solution as well as the deposition time. Prolonged growth leads to the formation of island-like aggregates or almost continuous lines. Nanocrystals preserve their strong luminescence when deposited into channels, which makes the fabricated periodic structures promising for optoelectronic applications.

We present a probe concept for scanning near-field optical microscopy combining the excellent background suppression of aperture probes with the superior light confinement of apertureless probes. A triangular aperture at the tip of a tetrahedral waveguide (full taper angle approximately 90 degrees ) shows a strong field enhancement at only one rim when illuminated with light of suitable polarization. Compared to a circular aperture of equivalent size, the resolution capability is doubled without loss of brightness. For a approximately 60 nm sized triangular aperture, we measured an optical resolution <40 nm and a transmission of approximately 10(-4).