Optical properties of rare-earth doped epitaxial Sr0.5Ba0.5Nb2O6 thin films grown by pulsed laser deposition

• Published in: Thin solid films Vol. 519; no. 1; pp. 52 - 57
• Main Authors: YAO, Y. B, LIU, W. C, MAY, C. L, WONG, K. H, TAM, H. L, CHEAH, K. W
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 29.10.2010
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Dopants; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Emission; Epitaxial growth; Exact sciences and technology; Laser deposition; Magnesium oxide; Materials science; Mechanical and acoustical properties; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physical properties of thin films, nonelectronic; Physics; Pulsed laser deposition; Rare earth metals; Residual stress; Surface and interface electron states; Surface states, band structure, electron density of states; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thick films; Thin films; Band structure; Barium; Electronic properties; Transparency; Epitaxial layers; Doping; Photoluminescence; Rare-earth doping; Strontium Barium Niobiate; Pulsed laser deposition; Residual stresses; Epitaxial film; Raman spectroscopy; Thin films; Strontium; Energy gap; Monocrystals; Optical properties; Barium strontium niobate; Laser ablation technique; Barium Strontium Niobates Mixed; Strontium bismuth niobate
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2010.07.059

Optical quality rare-earth (RE) (Nd3+, Eu3+, Gd3+ and Yb3+) doped Sr0.5Ba0.5Nb2O6 (SBN) epitaxial films of ~170nm thick have been successfully grown on MgO (100) single crystal substrates using pulsed laser deposition technique. Strong residual stress in these films has been revealed by Raman spectroscopic studies. Two kinds of in-plane orientations with respect to the MgO substrate co-exist. All the film samples show high transparency in the visible wavelength. Their band-gap energies appear to be independent of the types of dopant. Photoluminescence (PL) spectra of RE-doped SBN ceramics show a strong and broad emission band at around 600nm (2.07eV). The peak position of this emission band changes slightly with different RE-dopants. Thin film samples, however, yield a broad PL band at around 385nm (3.22eV). This UV emission shows no observable shift in the peak position for different dopants. Apart from these broad emission bands, conspicuous emission lines from Eu3+ and Nd3+ ions are also noted. The origins of these PL spectra are discussed.