Loading...

Role of nitrogen doping at the surface of titanium nitride thin films towards capacitive charge storage enhancement

Achour, A ; Sharif University of Technology

1021 Viewed
  1. Type of Document: Article
  2. DOI: 10.1016/j.jpowsour.2017.05.074
  3. Abstract:
  4. We recently reported an impressive cycling stability (over 20,000 cycles) of titanium nitride (TiN) electrodes with high specific capacitance. It is anticipated that nitrogen (β−N) doping in the oxidized surface of TiN film plays a crucial role in charge storage mechanism and stability of this material. In this work, we offer an evidence on the effect of β−N doping on improvement in specific capacitance of vacuum annealed TiN thin films. The annealing of the TiN films leads to the diffusion of the excess β−N from sub-surface to oxidized TiN film surface without further oxidation of the electrode surface. We demonstrate an increase in the TiN areal capacitance upon an increase in the amount of β−N dopant. The areal capacitance of the annealed films was enhanced by 3-fold (8.2 mF cm−2 in K2SO4 aqueous electrolyte) without sacrificing the cycling stability of the electrodes after more than 10,000 consecutive charge/discharge cycles. © 2017 Elsevier B.V
  5. Keywords:
  6. Electrochemical capacitors ; Nitrogen doping ; Oxidized surface ; Annealing ; Capacitance ; Electrodes ; Electrolytes ; Metallic films ; Nitrides ; Nitrogen ; Oxidation ; Semiconductor doping ; Thin films ; Titanium ; Titanium compounds ; Charge/discharge cycle ; Electrochemical capacitor ; High specific capacitances ; Oxidized surfaces ; Specific capacitance ; Thermal-annealing ; Titanium nitride thin films ; Titanium nitride
  7. Source: Journal of Power Sources ; Volume 359 , 2017 , Pages 349-354 ; 03787753 (ISSN)
  8. URL: https://www.sciencedirect.com/science/article/abs/pii/S0378775317307255