Enhanced anti-stocks luminescence in LaNbO₄:Ln³⁺ (Ln³⁺ = Yb³⁺, Er³⁺/Ho³⁺/Tm³⁺) with abundant color

Abstract

A 980 nm laser was employed to excite Yb3+ ions to achieve the 2F7/2 → 2F5/2 transition, and the LNO:Yb3+, Er3+/Ho3+/Tm3+ samples exhibited intense green, yellowish-green and blue emission, respectively.

Low-Temperature Solid-State Synthesis and Upconversion Luminescence Properties in (Na/Li)Bi(MoO4)2:Yb3+,Er3+ and Color Tuning in (Na/Li)Bi(MoO4)2:Yb3+,Ho3+,Ce3+ Phosphors

“…2−10 Among all the lanthanide ions from element lanthanum (La) to lutetium (Lu), Tm 3+ , Er 3+ , and Ho 3+ are the most three frequently utilized ions for UCL because of their abundant ladderlike energy levels with long lifetimes. 11,12 They, therefore, can generate blue, green, and red emissions upon 975 nm laser diode (LD) pump. However, their intra 4f−4f spin-forbidden transitions shielded by outer shells 5s 2 and 5p 6 lead to sharp and narrow emission lines with overall low intensity, which can be highly improved using Yb 3+ as a sensitizer for them, since it has a large absorption cross section around 975 nm and can efficiently transfer its absorbed energy to them.…”

“…Upconversion luminescence (UCL), a phenomenon absorbing and converting near-infrared (NIR) radiation into visible emission, can take place in certain rare-earth ion-doped materials . These luminescence materials have been extensively investigated for a variety of potential applications in solid-state laser, lighting and display, fluorescent labeling, drug delivery, solar energy, biological technique, temperature sensors, anticounterfeit, and information storage. − Among all the lanthanide ions from element lanthanum (La) to lutetium (Lu), Tm 3+ , Er 3+ , and Ho 3+ are the most three frequently utilized ions for UCL because of their abundant ladderlike energy levels with long lifetimes. , They, therefore, can generate blue, green, and red emissions upon 975 nm laser diode (LD) pump. However, their intra 4f–4f spin-forbidden transitions shielded by outer shells 5s 2 and 5p 6 lead to sharp and narrow emission lines with overall low intensity, which can be highly improved using Yb 3+ as a sensitizer for them, since it has a large absorption cross section around 975 nm and can efficiently transfer its absorbed energy to them. , It is well-known that the UCL intensity of a phosphor is largely dependent on the host materials, which means the lower phonon energy the material is, the better UCL properties may be.…”

Intense Single Red Emission Induced by Near‐Infrared Irradiation Using a Narrow Bandgap Oxide BiVO4 as the Host for Yb3+ and Tm3+ Ions

“…Among these, the 1 G 4 → 3 H 6 (≈475 nm) emission is the most intense, so that the color of Tm 3+ doped materials appear as blue in the upconversion or downconversion luminescence process. The DRS and UCL spectra of LaNbO 4 :Yb 3+ ,Tm 3+ (Figure b) show that the 1 D 2 → 3 H 6 emission of Tm 3+ is not detected in the LaNbO 4 host, and the color of LaNbO 4 : Yb 3+ ,Tm 3+ is blue again due to the intense 1 G 4 → 3 H 6 (≈475 nm) emission. The DRS and UCL spectra of BiVO 4 :Yb 3+ ,Tm 3+ (Figure c) show that the 1 G 4 → 3 H 6 (≈475 nm) emission became very weak, most likely because the 1 G 4 → 3 H 6 (≈475 nm) emission is absorbed by the host BiVO 4 to induce the excitation across its bandgap (≈520 nm).…”

Highly sensitive optical temperature sensing based on pump-power-dependent upconversion luminescence in LiZnPO4:Yb3+–Er3+/Ho3+ phosphors

“…11,12 The traditional activator ions for UC Luminescence (UCL) are Er 3+ , Ho 3+ , Tb 3+ and Tm 3+ . 6,[13][14][15] Because of its large absorption portion about 980 nm, the Yb 3+ ion is commonly used as a sensitizer to increase anti-stocks emissions. 16,17 On the basis of the rare-earth doped UCL materials, two strategies established to realize the FIR technique, containing thermally coupled levels (TCLs) and non-thermallycoupled levels (NTCLs).…”