Microstructure, photoluminescent properties and application of ZnO films grown on Al foils

Abstract

To obtain safety working before long-term early warning, we proposed a process for the preparation of luminescent films on metal substrate to detect the wear life. ZnO films were prepared on aluminum (Al) foils by the magnetron sputtering technique. The microstructure, tribological properties and photoluminescence (PL) spectra of ZnO films before and after the friction test were investigated. The microstructure of ZnO films grown on Al foils exhibited a closely packed hexagonal cone shape. ZnO films were grown along the orientation perpendicular to the substrate. The tribometric tests revealed that the average friction coefficient of ZnO films was lower and more stable than that of the substrate. The results of PL spectra indicated that the effect of Al element on ZnO films led to shifts of the defect related visible band. The luminescent center of ZnO films shifted from the emission peak at 510 nm before the friction to 647 nm after the friction, indicating that the green light shifted into the red light as the friction occurred. The visible light was helpful to understanding the failure characteristics during the friction and wear, and provide an early indicator of the impending failure.

Keywords

ZnO films / photoluminescence / friction and wear / the failure

References

[1] Muratore C, Clarke DR, Jones JG, et al. Voevodin. Smart Tribological Coatings with Wear Sensing Capability [J]. Wear, 2008, 265: 913-920.

[2] Gentleman MM, Clarke DR. Concepts for Luminescence Sensing of Thermal Barrier Coatings [J]. Surf. Coat. Technol., 2004, 188–189: 93-100.

[3] Heeg B, Clarke DR. Non-destructive Thermal Barrier Coating (TBC) Damage Assessment Using Laser-induced Luminescence and Infrared Radiometry [J]. Surf. Coat. Technol., 2005, 200: 1 298-1 302.

[4] Eldridge JI, Bencic TJ. Monitoring Delamination of Plasma-Sprayed Thermal Barrier Coatings by Reflectance-enhanced Luminescence [J]. Surf. Coat.Technol., 2006, 201: 3 926-3 930.

[5] Ozgur U, Alivov YI, Liu C, et al. A Comprehensive Review of ZnO Materials and Devices [J]. J. Appl. Phys., 2005, 98: 1-103.

[6] Bang JS, Yang HS, Paul HH. Enhanced and Stable Green Emission of ZnO Nanoparticles by Surface Segregation of Mg [J]. Nano. Technol., 2006, 17: 973-978.

[7] Vaidyanathan S, Eduardo EW, Prashant VK. Green Emission to Probe Photoinduced Charging Events in ZnO-Au Nanoparticles Charge Distribution and Fermi-Level Equilibration[J]. J. Phys. Chem. B, 2003, 107: 7 479-7 485.

[8] Lee JB, Kim HJ, Kim SG, et al. Deposition of ZnO Thin Films by Magnetron Sputtering for a Film Bulk Acoustic Resonator [J]. Thin Solid Films, 2003, 435: 179-185.

[9] Wang QP, Zhang DH, Xue ZY, et al. Mechanisms of Green Emission from ZnO Films Prepared by rf Magnetron Sputtering [J]. Opt. Mater., 2004, 26: 23-26.

[10] Rakhshani AE, Kokaj J, Mathew J, et al. Successive Chemical Solution Deposition of ZnO Flms on Fexible Steel Substrate: Structure, Photoluminescence and Optical Transitions [J]. Appl. Phys. A., 2007, 86: 377-383.

[11] Rasheva Z, Zhang G, Burkhart T. A Correlation between the Tribological and Mechanical Properties of Short Carbon Fibers Reinforced PEEK Materials with Different Fiber Orientations[J]. Tribol. Inter., 2010, 43: 1 430-1 437.

[12] Gilbert CJ, Ager JW, Schroeder V, et al. Light Emission during Fracture of a Zr-Ti-Ni-Cu-Be Bulk Metallic Glass[J]. Appl. Phys. Lett., 1999, 74: 3 809-3 811.

[13] Chakravarty A, Phillipson TE. Triboluminescence and the Potential of Fracture Surfaces[J]. J. Phys. D: Appl. Phys., 2004, 37: 2 175-2 180.

[14] Zhou HM, Yi DQ, Yu ZM, et al. Preparation of Aluminumdoped Zinc Oxide Films and the study of Their Microstructure, Electrical and Optical Properties [J]. Thin Solid Films, 2007, 515: 6 909-6 914.

[15] Bhupendra KS, Neeraj K, Haranathb D. Photoluminescence Lifetime of Al-doped ZnO Films in Visible Region [J]. Solid State Commun., 2010, 150: 2 341-2 345.