One-dimensional Thue-Morse (ThMo) lattices are examples of self-similar structures that exhibit bandgap phenomena. ThMo multilayers may also possess fractal photonic bandgaps that give rise to large omnidirectional reflectance and light emission enhancement effects. Two-dimensional (2D) ThMo aperiodic quasicrystals possess interesting properties for photonic applications too. Here we demonstrate the experimental fabrication of large area 2D ThMo lattices into polymeric substrates at nanometer scale by electron beam lithography (EBL). Far field diffraction patterns of the experimental Thue-Morse structures have been measured and compared with the calculated theoretical Fourier spectra. Scanning electron microscopy and far field diffraction are used to characterize the experimental structures.

We report a postfabrication process for the realization of nanosized light emitting diodes. The method is based on the exposure of the device to an Ar+ laser through an aperture near field optical microscope and can produce a large (>100 fold) increase in the electroluminescence within a near field hot spot as small as 440 nm. A study of morphological, photoluminescence and electroluminescence properties highlights the interplay between oxidation, annealing, and ablation processes for various laser exposure conditions.

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