Micro-ultracapacitors with highly doped silicon nanowires electrodes
1 Laboratory for Molecular Electronics Organic & Hybrid (LEMOH)-SPrAM UMR 5819 (CEA,CNRS, UJF), Grenoble, 38054, France
2 SiNaPS Laboratory SP2M, UMR-E CEA/UJF-Grenoble 1, Grenoble, 38054, France
3 Commisioner for Atomic Energy and Alternative Energies (CEA) Grenoble/INAC 17 Rue des Martyrs, Grenoble Cedex 9, 38054, France
4 Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 Rue de la Houssinière, BP32229, Nantes, Cedex 3, 44322, France
Nanoscale Research Letters 2013, 8:38 doi:10.1186/1556-276X-8-38Published: 21 January 2013
Highly n-doped silicon nanowires (SiNWs) with several lengths have been deposited via chemical vapor deposition on silicon substrate. These nanostructured silicon substrates have been used as electrodes to build symmetrical micro-ultracapacitors. These devices show a quasi-ideal capacitive behavior in organic electrolyte (1 M NEt4BF4 in propylene carbonate). Their capacitance increases with the length of SiNWs on the electrode and has been improved up to 10 μFcm−2 by using 20 μm SiNWs, i.e., ≈10-fold bulk silicon capacitance. This device exhibits promising galvanostatic charge/discharge cycling stability with a maximum power density of 1.4 mW cm−2.