Luminescent and crystalline properties of blue–white-emitting nanocrystalline Sr2CeO4 thin films produced by laser ablation

✍ Scribed by Néstor Perea; G.A. Hirata

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 314 KB
• Volume: 27
• Category: Article
• ISSN: 0925-3467
• DOI: 10.1016/j.optmat.2004.11.013

✦ Synopsis

Blue-white luminescent Sr 2 CeO 4 thin films were deposited by using pulsed laser ablation (k = 248 nm wavelength) on 500 °C silicon (1 1 1) substrates under an oxygen pressure of 55 mTorr. High-resolution electron transmission microscopy and X-ray diffraction analysis revealed that the films were composed of nanocrystalline Sr 2 CeO 4 grains of the order of 20-30 nm with a preferential orientation in the (1 3 0) crystallographic direction. The excitation and photoluminescence spectra measured on the films maintained the characteristic emission of Sr 2 CeO 4 however, the emission peak appeared narrower and blue-shifted as compared to the luminescence spectrum of the target. This blue-shift of about 10 nm may be related to the nanocrystalline nature of the grains and the preferential crystallographic orientation during the growth formation of the film.