Effect of Ga3+ and Gd3+ ions substitution on the structural and optical properties of Ce3+‐doped yttrium aluminium garnet phosphor nanopowders. (9th March 2016)

• Record Type: Journal Article
• Authors: Wako, A. H.; Dejene, F. B.; Swart, H. C.
• Is Part Of: Luminescence. Volume 31:Number 7(2016)
• Page Start: 1313
• Page End: 1320
• Publication Date: 2016-03-09
• Subjects: Y3(Al, Ga)5O12:Ce3+ -- (Y, Gd)3Al5O12:Ce3+ substitution -- thermoluminescence -- trap depths; Luminescence -- Periodicals; Bioluminescence -- Periodicals; Chemiluminescence -- Periodicals; Luminescence -- Periodicals; 535.35
• DOI: 10.1002/bio.3108
• Languages: English
• ISSNs: 1522-7235

Abstract

Abstract: The structural and optical properties of commercially obtained Y3 Al5 O12 :Ce 3 + phosphor were investigated by replacing Al 3 + with Ga 3 + and Y 3 + with Gd 3 + in the Y3 Al5 O12 :Ce 3 + structure to form Y3 (Al, Ga)5 O12 :Ce 3 + and (Y, Gd)3 Al5 O12 :Ce 3 + . X‐Ray diffraction (XRD) results showed slight 2‐theta peak shifts to lower angles when Ga 3 + was used and to higher angles when Gd 3 + was used, with respect to peaks from Y3 Al5 O12 :Ce 3 + and JCPDS card no. 73–1370. This could be attributed to induced crystal‐field effects due to the different ionic sizes of Ga 3 + and Gd 3 + compared with Al 3 + and Y 3 + . The photoluminescence (PL) spectra showed broad excitation from 350 to 550 nm with a maximum at 472 nm, and broad emission bands from 500 to 650 nm, centred at 578 nm for Y3 Al5 O12 :Ce 3 + arising from the 5d → 4f transition of Ce 3 + . PL revealed a blue shift for Ga 3 + substitution and a red shift for Gd 3 + substitution. UV–Vis showed two absorption peaks at 357 and 457 nm for Y3 Al5 O12 :Ce 3 +, with peaks shifting to 432 nm for Ga 3 + and 460 nm for Gd 3 + substitutions. Changes in the trap levels or in the depth and number of traps due to Ce 3 + were analysed using thermoluminescence (TL) spectroscopy. This revealed the existence of shallow and deep traps. It was observed that Ga 3 + substitution contributes to the shallowest traps at 74 °C and fewer deep traps at 163 °C, followed by Gd 3 + with shallow traps at 87 °C and deep traps at 146 °C. Copyright © 2016 John Wiley & Sons, Ltd.