Gagan Kumar Sharma, Bhanu Ranjan and Davinder Kaur*FUNCTIONAL NANOMATERIALS RESEARCH LAB

DEPARTMENT OF PHYSICS & CENTER FOR NANOTECHNOLOGY

INDIAN INSTITUTE OF TECHNOLOGY ROORKEE

ROORKEE-247667, UTTARAKHAND, INDIA

*dkaurfph@iitr.ac.in

REACTIVELY SPUTTERED TiN/Ti/(Si/PSi) & TiN/SS THIN FILMS TOWARDS

SUPERCAPACITIVE ELECTRODE

ABSTRACT: There has been great interest in developing and refining more efficient energy storage devices that could be coupled with renewable energy sources. Particularly, nitride based

supercapacitors (SCs) have gained gigantic attention for futuristic device applications. Transition Metal Nitrides are promising candidate as supercapacitor electrode material because of their excellent

electrical conductivity and superior cycling stability. The Binder Free Titanium Nitride (TiN) thin films were deposited on Stainless Steel (SS) substrate using reactive DC magnetron sputtering for very

efficient supercapacitive electrode. The morphological, structural and electrochemical properties were systematically studied for the TiN thin films at different sputtering gas (Ar+N2) composition. From

the electrochemical studies, we have observe that the TiN thin films as a working electrode exhibits high specific capacitance at minimum scan rate (451 Fg-1 at 0.02Vs-1 in 1M KOH). Thus, this study

suggest that the TiN thin film is a potential candidate for energy storage devices at large scale applications.

RF Magnetron Sputtering Chamber

Deposited Thin Films

Porous Silicon (PSi) formation

Methods

Results and Conclusion

Introduction and Objective

The authors Gagan Kumar Sharma and Bhanu Ranjan would like to acknowledge the financial support provided by the Department of Science & Technology (DST) and University Grant Commission, India. This work was supported by the Nano Mission with

Reference number SR/NM/NT-1065/2015.

References:

[1] Ying Wu, and Yan Yu, Energy Storage Materials, 2018, 7, 30484.

[2] L Porto R, Bouhtiyya S, Pierson JF, Morel A, Capon F and Boulet P, Electrochemical Acta, 2014, 141:203-11.

[3] Xie Y and Tian F, Material Science Eng B, 2017, 215:64-70.

[4] S Zhanga, F Yana, Y Yanga, M Yana, Y Zhanga, J Guoa and H Lib, Applied Surface Science, 2019, 48, 61-69.

[5] Theerthagiri, Jayaraman, et al., Journal of Industrial and Engineering Chemistry, 2018, 67 : 12-27.

[6] Ghosh, Subrata, Sang Mun Jeong, and Shyamal Rao Polaki., Korean Journal of Chemical Engineering, 2018, 35.7 : 1389-1408.

➢ Titanium Nitride (TiN) thin film as Supercapacitive electrode:

• The main goal of this work is to study the effect of gas composition on crystalline phase, electrical &

electrochemical properties of titanium nitride thin films on various substrates.

• Firstly, TiN/Ti deposited on Si(100) substrate by using reactive DC magnetron sputtering has been studied at

different Argon and Nitrogen gas compositions with fixed 20 SCCM gas flow rate.

• Secondly, TiN/Ti deposited on porous silicon (PSi) substrate by using reactive DC magnetron sputtering has been

studied and its Current-Voltage (I-V) & Cyclic Voltammetry (CV) Characteristics has been studied.

• Then, TiN thin film deposited on metallographically cleaned Stainless Steel (SS) substrate by using reactive DC

magnetron sputtering has been studied and its I-V & CV characteristics has also been studied.

Acknowledgements & References

(b)

I-V Characteristics for different samples

Cyclic Voltammetry (CV) Characteristics for Stainless Steel (SS)

Cyclic Voltammetry (CV) Characteristics for PSi

2D and 3D AFM Images of the as-deposited TiN thin film on Stainless Steel substrate: S1 (25% N2), S2 (50% N2), S3 (100% N2)

❖ Ti & TiN thin films deposited on Si(100) substrates by Reactive DC Magnetron sputtering using Ti target.

❖ For Ti deposition, working pressure (10 mTorr), substrate temperature (200 °C), sputtering power (150W),

deposition time (10 min).

❖ For TiN/Ti/(Si/PSi) deposition, working pressure (12 mTorr), substrate temperature (400 °C), sputtering

power (120W), deposition time (15 min).

❖ For TiN/SS deposition, working pressure (12 mTorr), substrate temperature (500 °C), sputtering power

(130W), deposition time (45 min).

➢ Structural and Morphological Characterization:

• The Crystalline nature of the as-deposited Titanium and Titanium Nitride thin film has been studied using X-Ray

Diffractometer (Bruker D8 advanced).

• The Morphology and surface roughness has been studied using the 2D and 3D AFM Images of the as-deposited

Titanium nitride thin film on Stainless Steel Samples: S1 (25% N2), S2 (50% N2), S3 (100% N2) using AFM (NT-

MDT-INTEGRA).

• The surface morphology of Porous Silicon and as-deposited Titanium Nitride thin film has been studied using FE-

SEM (FEI Quanta 250 FEG-SEM).

➢Electrochemical Characterization :

• Cyclic Voltammetry (CV) of TiN/SS working electrode at different scan rates: 0.02Vs-1, 0.06Vs-1, 0.10Vs-1and

0.12Vs-1 in 1M KOH electrolyte has been studied using Nova Control Cyclic Voltammetry setup.

• Cyclic Voltammetry (CV) of TiN/PSi working electrode at different scan rates: 0.02Vs-1, 0.06Vs-1, 0.10Vs-1and

0.12Vs-1 in 1M KOH electrolyte has also been studied.

➢Electrical Characterization:

▪ The electrical characterization (I-V) of TiN/Ti , TiN/Ti/PSi and TiN/SS within potential window (-1V to +1V)

performed by Semiconductor Characterization system (Keithley 4200-SCS) and studied.

(S1) (S2) (S3)

FE-SEM Images of TiN/SS working electrode at different scales

(b) (c)

XRD Pattern of Ti and TiN

FE-SEM Images of PSi and Ti/PSi

Conclusion:

▪ TiN/Ti/Si , TiN/Ti/PSi and TiN/SS thin films have been successfully deposited

using reactive DC magnetron sputtering.

▪ Electrochemical studies shows that TiN/SS delivers a high specific capacitance

of about 451F/g at scan rate of 0.02Vs-1.

▪ The sputtering technique is recommended as a facile and versatile deposition

technique to achieve contamination and binder free electrodes for high

performance electrodes.

▪ There is a enhancement in the electrochemical performance due to the

introduction of pores in the silicon.

▪ The various sputtering parameters like deposition temperature were optimised

keeping just the base pressure constant at 2×10-6 Torr.

(b)