VUV–UV Photoluminescence Spectra of Strontium Orthophosphate Doped with Rare Earth Ions

✍ Scribed by Hongbin Liang; Ye Tao; Qiang Su; Shubin Wang

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 226 KB
• Volume: 167
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2002.9651

✦ Synopsis

The measurements of VUV-UV photoluminescence emission (PL) and photoluminescence excitation (PLE) spectra of rare earth ions activated strontium orthophosphate [Sr 3 (PO 4 ) 2 :RE, RE = Ce, Sm, Eu, Tb] are performed. Whenever the samples are excited by VUV or UV light, the typical emission of Ce 3+ , Sm 3+ , Eu 3+ , Eu 2+ and Tb 3+ ions can be observed in PL spectra, respectively. The charge transfer bands (CTBs) of Sm 3+ and Eu 3+ are found, respectively, peaking at 206 and 230 nm. The absorption bands peaking in the region of 150-160 nm are assigned to the host lattice sensitization bands, i.e., the band-to-band transitions of PO 4 3À grouping in Sr 3 (PO 4 ) 2 . It is speculated that the first f-d transitions of Sm 3+ (Eu 3+ ), and the CTB of Tb 3+ are, respectively, located around 165 (1 4 3) and 167 nm by means of VUV-UV PLE spectra and relational empirical formula, these f-d transitions or CT bands are included in the bands with the maxima at 150-160 nm, respectively. The valence change of europium from trivalent to divalent in strontium orthophosphate prepared in air is observed by VUV-UV PL and PLE spectra.