Three‐Dimensional self‐organization in nanocomposite layered systems by ultrafast laser pulses

10 pags., 6 figs.Controlling plasmonic systems with nanometer resolution in transparent films and their colors over large nonplanar areas is a key issue for spreading their use in various industrial fields. Using light to direct self-organization mechanisms provides high-speed and flexible processes to meet this challenge. Here, we describe a route for the laser-induced self-organization of metallic nanostructures in 3D. Going beyond the production of planar nanopatterns, we demonstrate that ultrafast laser-induced excitation combined with nonlinear feedback mechanisms in a nanocomposite thin film can lead to 3D self-organized nanostructured films. The process, which can be extended to complex layered composite systems, produces highly uniform large-area nanopatterns. We show that 3D self-organization originates from the simultaneous excitation of independent optical modes at different depths in the film and is activated by the plasmon-induced charge separation and thermally induced NP growth mechanisms. This laser color marking technique enables multiplexed optical image encoding and the generated nanostructured Ag NPs:TiO2 films offer great promise for applications in solar energy harvesting, photocatalysis, or photochromic devices.This work was funded by the French Research Agency (ANR) in the framework of project PHOTOFLEX 12-NANO-0006 and programs ANR-10-LABX-0075 (Labex MANUTECHSISE) and ANR-11-IDEX-0007. It has also been supported by the LiNaBioFluid project (H2020-FETOPEN-2014- 2015RIA, grant 665337) of the European Commission, as well as by a research grant (TEC2014-52642-C2-1-R) from the Spanish Ministry of Economy and Competitiveness. M.G.-L. thanks the Spanish Ministry of Education for a FPU fellowship. The authors thank CLYM (www.clym.fr) for access to the Jeol 2010F TEM and the FEI Titan ETEM G2 80-300. GIE MANUTECH-USD is acknowledged for providing access to the FEI Dual Beam Helios600i.Peer reviewe