Final Report Summary - NANO-JETS (Next-generation polymer nanofibers: from electrified jets to hybrid optoelectronics)
The NANO-JETS project had as final objective the use of active polymer nanofibers to realize cavity-free lasers. This goal was fully achieved through the accomplishment of a high number of scientific and technological results, which went well beyond the state of the art of organic and composite nanomaterials. The process of electrospinning, which is based on stretching polymer solutions by intense applied electric fields, was critically developed to produce various new species of active nanofibers. Examples of obtained fibrous materials included systems based on conjugated polymers, nanocrystals and light-emitting dyes used as dopants, molecular complexes, carbon nanotubes, fullerenes, two-dimensional materials, and piezoelectric compounds. The process for realizing nanofibers was modelled, which led to the release of JETSPIN, a specific-purpose open-source software which has been made publicly available. Furthermore, jets generated during electrospinning were imaged at 10,000 frames per second, studying the instabilities affecting the process while aiming to obtain more finely controllable fibers. Electrospinning under controlled atmosphere was also implemented to realize more reliable and stable light-emitting organic materials. The stimulated emission, the optical gain in the ultraviolet, visible, and near-infrared spectral range, and the transport of light in the fibrous systems (i.e. from individual polymer filaments to complex networks), were studied, leading to the discovery of several unconventional properties. Finally, lasers based on networks of nanofibers were realized by a variety of configurations, and studied in their fundamental features as well as in their device characteristics. These light-emitting nanofibers were so demonstrated to be a highly versatile, effective and smart class of materials for nanophotonics and energy harvesting technologies, and an excellent platform for highlighting new optical and electronic phenomena at nanoscale.