Titanium nitride films for micro-supercapacitors: Effect of surface chemistry and film morphology on the capacitance Amine Achour a, b , Raul Lucio Porto c, d , Mohamed-Akram Soussou e , Mohammad Islam f , Mohammed Boujtita g , Kaltouma Ait Aissa h , Laurent Le Brizoual h , Abdou Djouadi h , Thierry Brousse h, i, * a Laboratoire d'analyse et d'architecture des syst emes (LAAS), CNRS, 7 Avenue du Colonel Roche, 31400, Toulouse, France b L'ecole Nationale Polytechnique de Constantine P 75, A, Nouvelle ville RP, Constantine, Algeria c Universidad Aut onoma de Nuevo Le on, Facultad de Ingeniería Mec anica y El ectrica, San Nicol as de los Garza, 66450, Nuevo Le on, Mexico d Universidad Aut onoma de Nuevo Le on, Centro de Innovaci on, Investigaci on y Desarrollo en Ingeniería y Tecnología, Apodaca, 66600, Nuevo Le on, Mexico e LaPhyMNE, University of Gabes, Cit e Erriadh, 6072, Zrig, Gabes, Tunisia f College of Engineering, King Saud University, P.O. Box 800, Riyadh,11421, Saudi Arabia g CEISAM, Universite de Nantes, CNRS, 2 rue de la Houssiniere, BP 32229, 44322, Nantes Cedex 3, France h Institut des Mat eriaux Jean Rouxel (IMN), Universit e de Nantes, CNRS, 2 rue de la Houssini ere, BP32229, 44322, Nantes Cedex 3, France i R eseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS, 3459, France highlights  Titanium nitride films have been deposited with different morphologies.  The electrode exhibits a specific capacitance in excess of 146 F cm 3 .  The effect of TiN stoichiometry on film capacitance has been demonstrated. article info Article history: Received 16 December 2014 Received in revised form 31 July 2015 Accepted 2 September 2015 Keywords: TiN films Electrochemical capacitors DC-sputtering Porous films abstract Electrochemical capacitors (EC) in the form of packed films can be integrated in various electronic de- vices as power source. A fabrication process of EC electrodes, which is compatible with micro-fabrication, should be addressed for practical applications. Here, we show that titanium nitride films with controlled porosity can be deposited on flat silicon substrates by reactive DC-sputtering for use as high performance micro-supercapacitor electrodes. A superior volumetric capacitance as high as 146.4 F cm 3 , with an outstanding cycling stability over 20,000 cycles, was measured in mild neutral electrolyte of potassium sulfate. The specific capacitance of the films as well as their capacitance retentions were found to depend on thickness, porosity and surface chemistry of electrodes. The one step process used to fabricate these TiN electrodes and the wide use of this material in the field of semiconductor technology make it promising for miniaturized energy storage systems. © 2015 Elsevier B.V. All rights reserved. 1. Introduction There is an increasing demand for miniaturization and boosting the performance of the wide spread multifunctional electronic devices and micro electromechanical systems (MEMS) for more challenging and smart environments [1,2]. An integrated micro- scale power source can play a major role in device reliability and performance enhancement during operation [3], underlining the need to develop such power sources. Electrochemical capacitors, also called supercapacitors, should be suitable for on-chip inte- gration alongside the circuit they power because of their excellent chargeedischarge rate and long operating lifetime as compared to the existing micro-batteries [1]. The key issues to be addressed in developing miniaturized supercapacitors, also referred to as micro- supercapacitors, are; improvement of volumetric/areal energy density, maintaining good cycling stability and use of electrode * Corresponding author. Institut des Mat eriaux Jean Rouxel (IMN), Universit e de Nantes, CNRS, 2 rue de la Houssini ere, BP32229, 44322 Nantes Cedex 3, France. E-mail address: thierry.brousse@univ-nantes.fr (T. Brousse). Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour http://dx.doi.org/10.1016/j.jpowsour.2015.09.012 0378-7753/© 2015 Elsevier B.V. All rights reserved. Journal of Power Sources 300 (2015) 525e532