Field Emission Properties of Nano-DLC Films Prepared on Cu Substrates by Pulsed Laser Deposition

Abstract

Nano-diamond like carbon (DLC) thin films were prepared on fused silica and Cu substrates by the pulsed-laser deposition technique with different laser intensities. Step-measurement, atomic force microscope (AFM), UV-VIS-NIR transmittance spectroscopy and Raman spectroscopy were used to characterize the films. It was shown that the deposition rate increases with the laser intensity, and the films prepared under different laser intensities show different transparency. Raman measurement showed that the content of sp³ of the Nano-DLC thin films decreases with the laser intensity. The field emission properties of the Nano-DLC thin films on Cu substrates were studied by the conventional diode method, which showed that the turn-on field increases and the current density decreases with sp³ content in the films. A lower turn-on field of 6 V/um and a higher current density of 1 uA/cm² were obtained for Nano-DLC thin films on Cu substrate.

Keywords

nano-DLC thin films / pulsed-laser deposition / field emission properties

References

[1] Baker FS, Osborn AR, Williams J. Field Emission from Carbon Fibres: A New Electron Source[J]. J. Phys. D: Appl. Phys., 1974, 7(5367): 2 105-2 110.

[2] Ogwu AA, Okpalugo TIT, Mclaughlin JAD. The Effect of PECVD Plasma Decomposition on the Wettability and Dielectric Constant Changes in Silicon Modified DLC Films for Potential MEMS and Low Stiction Applications[J]. AIP Advances, 2012, 2(3): 032128

[3] Wu YX, Chen JM, Li HX, et al. Preparation and Properties of Ag/DLC Nanocomposite Films Fabricated by Unbalanced Magnetron Sputtering[J]. Appl. Surf. Sci., 2013, 284: 165-170.

[4] Roman WS, Riascos H, Caicedo JC, et al. Nanostructures Based in Boronitride Thin Films Deposited by PLD onto Si/Si3N4/DLC Substrate[J]. J. Phys. Conference Series, 2009, 167(1): 012004-09.

[5] Wang XM, Wu WD, Li SY, et al. Properties of W Incorporated Diamond- like Carbon Films Prepared by Pulsed-laser Deposition[J]. J. Alloy. Compd., 2009, 479(1): 741-749.

[6] Lubwama M, Corcoran B, Rajani KV, et al. Raman Analysis of DLC and Si-DLC Films Deposited on Nitrile Rubber[J]. Surf. & Coat. Tech., 2013, 232: 521-527.

[7] Li RS, Xie EQ, Zhou M, et al. Field Emission Properties of Nitrogen Incorporated DLC Films Prepared by Electrodeposition[J]. Appl. Surf. Sci., 2008, 255(5): 2 787-2 790.

[8] Firrari AC, Robertson J. Resonant Raman Spectroscopy of Disordered, Amorphous, and Diamondlike Carbon[J]. Phys. Rev. B, 2001, 64: 075414-21.

[9] Casiraghi C, Firrari AC, Robertson J. Raman Spectroscopy of Hydrogenated Amorphous Carbons[J]. Phys. Rev., B, 2005, 72: 085401-14.

[10] Cui WG, lai QB, Zhang L, et al. Quantitative Measurements of sp3 Contents in DLC Films with Raman Spectroscopy[J]. Surace & Cating Technology, 2010, 205(7): 1 995-1 999.

[11] Liu E, Shi X, Tay BK, et al. Micro-Raman Spectroscopic Analysis of Tetrahedral Amorphous Carbon Films Deposited under Varying Conditions[J]. J. Appl. Phys., 1999, 86(11): 6 078-6 083.

[12] Irmer G, Dorner-Reisel A. Micro-Raman Studies on DLC Coatings [J]. Adv. Eng. Mater., 2005, 7(8): 694-705.

[13] Sheeja D, Tay BK, Lau SP, et al. Structural and Tribological Characterization of Multilayer Ta-C Films Prepared by FCVA with Substrate Pulse Biasing[J]. Surf. Coat. Technol., 2000, 132(2): 228-232.

[14] Capano MA, McDevitt NT, Singh RK, et al. Characterization of Amorphous Carbon Thin Films[J]. J. Vac. Sci. Technol, 1995, 14(2): 431-435.

[15] Tauc J, Grigorovici R, Vancu A. Optical Properties and Electronic Structure of Amorphous Germanium[J]. Phys. Status Solidi, 1966, 15(2): 627-633.

[16] Xiao JR, Jiang AH. Effect of Radio Frequency Power on the Structural and Optical Properties of Nitrogen Doping of Fluorinated Diamond-like Carbon Thin Films[J]. J. Phys. D: Appl. Phys., 2008, 41(22): 225304-11.

[17] Nie GZ. Influence of Nitrogen Doping on Electron Structure and Optical Properties of Amorphous Carbon Thin Films, 2006

[18] Shakerzadeh M, Xu N, Bosman M, et al. Field Emission Enhancement and Microstructural Changes of Carbon Films by Single Pulse Laser Irradiation[J]. Carbon, 2011, 49(3): 1 018-1 024.

[19] Liu P, Wang CX, Chen J, et al. Local Nanodiamond Crystallization and Field Emission Performance Improvement of Amorphous Carbon upon Laser Irradiation in Liquid[J]. J. Phys. Chem. C, 2009, 113(28): 12 154-12 161.

[20] Wang J, Li YA, Gu GR, et al. Synthesis and Improved Electron Field Emission Characteristics of Au-coated Nano-carbon Needle Films[J]. Vacuum, 2011, 86(4): 356-360.

[21] Groing O K, Groing P, et al. Field Emission From DLC Films[J]. Appl. Surf. Sci., 1997, 111: 135-139.

[22] Huang BR, Yeh CS, Wang DC, et al. Field Emission Studies of Amorphous Carbon Deposited on Copper Nanowires Grown by Cathodic Arc Plasma Deposition[J]. New Carbon Material, 2009, 24(2): 97-101.