A new protocol for templated synthesis of YVO4:Ln luminescent crystallites (Ln=Eu, Dy, Sm)

Eroding the Surface of Rare Earth Microcrystals through Vanadate Ions for Considerable Improvement of Luminescence

“…The excitation spectrum consisted of a strong and broad absorption band ranging from 200 to 350 nm, which was assigned to the energy transfer from VO 3 − to Eu 3+ . The overlapped excitation was from 2 individual bands located at ~275 nm and ~323 nm, which corresponded to the transitions of 1 A 2 ( 1 T 1 )→ 1 E ( 1 T 2 ) and 1 A 2 ( 1 T 2 )→ 1 A 1 ( 1 E) of V 5+ , respectively [25,26]. The band at ~255 nm was the contribution of the O 2− -Eu 3+ charge transfer [7][8][9], while the very weak transitions of 7 F 0,1 → 5 L 6 and 7 F 0,1 → 5 D 2 at 395 nm and 463 nm for Eu 3+ were observed in the excitation spectra [7][8][9].…”

Extensive tailoring of REPO4 and REVO4 crystallites via solution processing and luminescence

“…1 A 1 ( 1 E) and 1 E ( 1 T 2 ) excited states of VO 4 3− under UV excitation, 89,90 (2) nonradiative relaxation of the absorbed excitation energy to the lowest lying 1 A 1 ( 1 A 1 ) excited state of VO 4…”

“…18 Fig. 6 schematically illustrates the process of VO 4 3− → Eu 3+ energy transfer, which includes (1) promotion of electrons from the 1 A 2 ( 1 T 1 ) ground state to 1 A 1 ( 1 E) and 1 E ( 1 T 2 ) excited states of VO 4 3− under UV excitation, 89,90 (2) nonradiative relaxation of the absorbed excitation energy to the lowest lying 1 A 1 ( 1 A 1 ) excited state of VO 4 3− followed by resonant energy transfer to the neighboring Eu 3+ , which may quench the luminescence of VO 4 3− itself ( 1 A 1 ( 1 A 1 ) → 1 A 2 ( 1 T 1 )) depending on the content of Eu 3+ , (3) excitation of Eu 3+ electrons from the F 0,1 ground state to 5 D 4 , 5 L 7 , 5 L 6 , 5 D 3 and 5 D 2 levels with the energy transferred from VO 4 3− , and (3) nonradiative relaxation to 5 D 1 and 5 D 0 levels, followed by radiative relaxation to 7 F J ground levels to produce the observed Eu 3+ luminescence. On the other hand, GdPO 4 is able to sensitize Ln 3+ luminescence through intra-4f 7 electronic transition of the host Gd 3+ ions, 91 and the visible-light emission of GdPO 4 :Tb under vacuum ultraviolet (VUV) excitation is promising for application in plasma display panels (PDPs).…”

Fabrication of REVO4 films via sacrificial conversion from layered rare-earth hydroxide (LRH) films: the investigation of the transition mechanism and their photoluminescence

“…15 Previous studies have shown that hydroxides are good candidates as sacrificial templates. 16 Layered rare-earth hydroxides (LRHs), with a general formula of RE 2 (OH) 5 NO − anions along the c-axis. 17,18 LRHs have attracted extensive attention since they were first reported in 2006 owing to the special layered structure and the properties of rare-earth elements, 19 which include interlayer anion exchange, 18,20,21 catalytic performance of intercalated products, 19,22,23 exfoliation of bulk crystals into nanosheets, [24][25][26] photoluminescence, 18,[26][27][28] and enhancement of luminescence.…”