Highly textured and transparent RF sputtered Eu2O3 doped ZnO films.

Sreedharan, Remadevi Sreeja; Ganesan, Vedachalaiyer; Sudarsanakumar, Chellappan Pillai; Bhavsar, Kaushalkumar; Prabhu, Radhakrishna; Pillai, Vellara Pappukutty Pillai Mahadevan

Abstract

Background: Zinc oxide (ZnO) is a wide, direct band gap II-VI oxide semiconductor. ZnO has large exciton binding energy at room temperature, and it is a good host material for obtaining visible and infrared emission of various rare-earth ions. Methods: Europium oxide (Eu2O3) doped ZnO films are prepared on quartz substrate using radio frequency (RF) magnetron sputtering with doping concentrations 0, 0.5, 1, 3 and 5 wt%. The films are annealed in air at a temperature of 773 K for 2 hours. The annealed films are characterized using X-ray diffraction (XRD), micro-Raman spectroscopy, atomic force microscopy, ultraviolet (UV)-visible spectroscopy and photoluminescence (PL) spectroscopy. Results: XRD patterns show that the films are highly c-axis oriented exhibiting hexagonalwurtzite structure of ZnO. Particle size calculations using Debye-Scherrer formula show that average crystalline size is in the range 15 22 nm showing the nanostructured nature of the films. The observation of low- and high-frequency E2 modes in the Raman spectra supports the hexagonal wurtzite structure of ZnO in the films. The surface morphology of the Eu2O3 doped films presents dense distribution of grains. The films show good transparency in the visible region. The band gaps of the films are evaluated using Tauc plot model. Optical constants such as refractive index, dielectric constant, loss factor, and so on are calculated using the transmittance data. The PL spectra show both UV and visible emissions. Conclusion: Highly textured, transparent, luminescent Eu2O3 doped ZnO films have been synthesized using RF magnetron sputtering. The good optical and structural properties and intense luminescence in the ultraviolet and visible regions from the films suggest their suitability for optoelectronic applications.

Citation

SREEDHARAN, R. S., GANESAN, V., SUDARSANAKUMAR, C. P., BHAVSAR, K., PRAHBU, R. and PILLAI, V.P.P.M., 2015. Highly textured and transparent RF sputtered Eu2O3 doped ZnO films. Nano reviews [online], 6, Article 26759. Available from: https://doi.org/10.3402/nano.v6.26759

• Journal Article Type: Article
• Acceptance Date: Jan 5, 2015
• Online Publication Date: Mar 11, 2015
• Publication Date: Dec 31, 2015
• Deposit Date: Mar 16, 2015
• Publicly Available Date: Mar 16, 2015
• Journal: Nano reviews
• Electronic ISSN: 2000-5121
• Publisher: Taylor and Francis
• Peer Reviewed: Peer Reviewed
• Volume: 6
• Article Number: 26759
• DOI: https://doi.org/10.3402/nano.v6.26759
• Keywords: Visible photoluminescence; Dielectric constants; MicroRaman spectra; Optical constants; Residual stress
• Public URL: http://hdl.handle.net/10059/1166
• Contract Date: Mar 16, 2015