Principal Investigator :

Vincent Paillard ()
CEMES (groupes nMat (Nanodyn) & MC2 (C. Gatel))

Type of project : Disruptive Project

Date (start/end) : 2015 - 2017

     

      

Abstract

Heavily doped semiconductor nanocrystals can mimic optical properties of plasmonic nanostructures of noble metals thanks to the appearance of a localized surface plasmon resonance (LSPR). However, the weaker free carrier concentration (10 ¹⁸ -10 ²¹ cm ^-3 ) compared to metals (10 ²² -10 ²³ cm ^-3 ) limits the domain of interest to the mid-infrared spectrum.

The aim of the LANCE project is to produce and study massively doped silicon nanocrystals (Si-NCs) in order to shift their plasmon resonance in the near-IR or visible range. Two different parts will be considered:

1- Large (> 20 nm diameter) massively doped (15-35 % dopant concentration) Si-NCs should exhibit LSPR in the 1.5-2.5 eV energy range. In many applications using plasmonic nanoantennas to increase the optical absorption and scattering or localize an intense electromagnetic field in the near-field of the nanostructures, doped Si-NCs could advantageously replace gold or silver nanoparticles for full compatibility with standard Si technology processes.

2- Small (2-4 nm diameter) heavily doped (10% dopant concentration) Si-NCs exhibit localized sharp absorption bands in the visible range due to LSPR, as predicted recently theoretically by Pi and Delerue (Phys. Rev. Lett. 111 , 177402 (2013)).

The LANCE project, based on a complete study of massively doped silicon nanostructures from their production to their structural and optical characterizations, is highly challenging and would open the possibility to verify experimentally for the first time the appearance of Localized Surface Plasmon Resonances in the visible range in non metallic nano-objects. It could open a route towards silicon-based plasmonic devices.