Nanosources and waveguiding in polymer-based nanowires and nanotubes

International audienceNano-architectures give opportunities to control and to tune the optoelectronic properties that could result in new paradigms for devices. Moreover, the 1D geometry promotes sub-wavelength optical propagation and cavity effects suitable for integrated nanophotonic devices.[1] First, we propose a novel strategy to get bright nano-emitters whose spectral emission can be precisely and simply anticipated. It consists in minimizing the role of charge and energy transfer mechanisms between the two species. The first key point is the selection of luminophores to prevent overlapping of their absorption and emission spectral range. The second key point is the spatial separation of the two types of luminophores in a coaxial geometry to prevent charge and energy transfer. [2] Coaxial nanowires with red emitters in the core and green fluorophores in the shell were successfully synthesized by a two-step template strategy. A simple and fine tuning of the photoluminescence features with both species in similar concentration has been shown. These advantages could make our strategy a new paradigm for nano-emitters. Second, experimental and FDTD modelling of light propagation along polymeric nanotubes has been investigated. The case of nanotubes is of particular interest because of higher interactions between the propagating light and both the surrounding medium and the inner channel. The light was directly injected within nanotubes of SU-8 photoresist. Using a cut-back like method, the attenuation coefficient has been estimated at about 10 dB/cm. [3] Thus, it shows that polymeric nanowires and nanotubes are very competitive structures as sub-wavelength waveguides. Recent developments focused on combining fluorescent conjugated molecules within passive polymeric nanotubes will also be reported.[1] A. Garreau, J.L. Duvail Advanced Optical Materials 2, 1122-1140 (2014)[2] A. Garreau et al., ACS Nano 7, 2977–2987 (2013)[3] J. Bigeon, N. Huby, J.L. Duvail, B. Bêche, Nanoscale 6, 5309 (2014