Photoluminescence and energy transfer in Tb3+/Mn2+ co-doped ZnAl2O4 glass ceramics

✍ Scribed by Gandham Lakshminarayana; Lothar Wondraczek

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 994 KB
• Volume: 184
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1016/j.jssc.2011.05.059

✦ Synopsis

We report on Tb 3 þ as efficient sensitizer for red photoemission from Mn 2 þ -centers in ZnO-B 2 O 3 -Al 2 O 3 -Si 2 O-Na 2 O-SrO glasses and corresponding gahnite glass ceramics. In comparison to singly or co-doped glasses, the glass ceramics exhibit significantly increased emission intensity. Structural considerations, ESR, and dynamic luminescence spectroscopy indicate partial incorporation of Mn 2 þ as well as Tb 3 þ into the crystalline phase, the former on octahedral Zn 2 þ -sites. Interionic distance and charge transfer probability between both species depend on crystallization conditions. This enables control of the energy transfer process and, hence, tunability of the color of photoemission by simultaneous emission from Tb 3 þ and Mn 2 þ centers. Concentration quenching in Mn 2 þ -singly doped materials was found at a critical dopant concentration of about 1.0 mol%. The energy transfer process was studied in detail by dynamic as well as static luminescence spectroscopy. Spectroscopic results suggest the application of the studied materials as single or dual-mode emitting phosphor for luminescent lighting.