Deep-red to near-infrared luminescence from Eu²⁺-trapped exciton states in YSiO₂N

Abstract

The valence state of Eu ions doped in inorganic compounds is easily influenced by the synthesizing condition. In this study, the X-ray absorption spectroscopy revealed that almost half of Eu...

Ultra‐Broadband Green‐Emitting Phosphors without Cyan Gap Based on Double‐Heterovalent Substitution Strategy for Full‐Spectrum WLED Lighting

“…[11d,f, 26 ] Moreover, in such matrix lattices, Eu 2+ ions in trivalent rare earth ion sites are prone to produce red or even near‐infrared emission due to large crystal field splitting (as a result of the small CNs and short bond length). [ 27 ] But the existence of Eu 3+ ions in trivalent rare earth ion sites (La 3+ in this work) is inevitable due to the same valence state and similar ion radius, as will be explained in Figure . Since multisite occupancies of Eu 2+ ions produce multiband luminescence, the tunable emissions can be achieved by adjusting preferred occupation of Eu 2+ at different sites.…”

Highly Stable Oxynitride Persistent Phosphors with Widely Distributed Traps for Information Storage and Anticounterfeiting

“…[ 13,14 ] Second, the trapped excitons degenerated from the 5d 1 level of Yb 2+ , similar to previous Eu 2+ and Yb 2+ doped phosphors, can be a possibility. [ 15 ] Finally, the emitting level of Yb 2+ should be very close to the conduction band minimum (CBM), thus the emission spectrum will be further broadened as Ba 2+ is substituted by Yb 2+ in a host. [ 9c,16 ] In this case, PersL can be readily observed due to the thermal stimulation, and detailed results will be given in the next context.…”

A brief review of characteristic luminescence properties of Eu3+ in mixed-anion compounds

“…5). 145 The co-existence of Eu 2+ ions significantly lowered the Eu 3+ luminescence intensity in the YSiO 2 N host. 15 The mechanism of this Eu reduction can be understood by using the Elingham diagram, which indicates that Eu is more easily reduced at higher temperatures in environments with low oxygen partial pressure.…”

“…The YSiO 2 N:Eu 3+ phosphor is the only Eu 3+ -doped oxynitride material that is synthesized and characterized. 15,67,145 To stabilize Eu 3+ ions in the oxynitride matrix, compounds containing trivalent yttrium ions Y 3+ , which have a similar ionic radius of 1.019 Å (CN = 8) to Eu 3+ (1.066 Å, CN = 8), 138 were explored. In the synthesis of the Eu 3+ -doped YSiO 2 N oxynitride, a two-step sintering process was necessary.…”