Multipath optical thermometry realized in CaSc₂O₄: Yb³⁺/Er³⁺ with high sensitivity and superior resolution

Abstract

Design and fabrication of contactless optical thermometer with rapid and accurate performance has become a research hotspot in recent years. Herein, CaSc2O4: Yb3+/Er3+ is employed as the intermediary for temperature sensing under the excitation of 980 nm, which is proven to afford an ultra‐sensitive and high‐resolution optical thermometry in multiple ways based on the fluorescence intensity ratio (FIR) technology. The optimal thermal sensing behaviors are realized by the FIR of Er3+:2H11/2 → 4I15/2 to 4S3/2 → 4I15/2 transition, which has a relative sensitivity of 1184/T2 and a minimal resolution of 0.03 K along with a maximal absolute error of 0.96 K. Besides that, the FIR between the thermally coupled Stark sublevels of Er3+:4F9/2 manifold (FIRR) as well as that of Er3+: 4I13/2 manifold (FIRN) can also provide excellent optical thermometry. The relative sensitivity of FIRR‐based and FIRN‐based optical thermometers are calculated to be 402/T2 and 366/T2, respectively, with a same minimal resolution of 0.09 K, which possess the potential to be used for biomedicine due to the inherent advantage of their operating wavelengths located in the biological window. The results demonstrate that CaSc2O4: Yb3+/Er3+ is a promising candidate for temperature sensing with multipath, high sensitivity, and superior resolution.

Eulytite-type Ba3Yb(PO4)3:Tm/Er/Ho as a high sensitivity optical thermometer over a broad temperature range

“…These results indicate that the energy gap of TCELs is approximately 725 cm −1 . For the TCELs associated with Er 3+ , the S a and S r can be expressed as: 48 The S a and S r values of Ba 3 Yb(PO 4 ) 3 :4% Er 3+ phosphor calculated by eqn (7) and (8), are illustrated in Fig. 6c.…”

Study on a Highly Thermostable Dy3+-Activated Borophosphate Phosphor

“…A clearly monotonic uptrend for the FIR with temperature in the range of 298–473 K is shown (Figure c). The crucial indices (absolute sensitivity ( S A ) and relative sensitivity ( S R )) for assessing temperature sensing performance can be determined through the following equations: S A = d FIR d T = FIR false( normalΔ E / T 2 false) S R = 1 FIR d FIR d T = Δ E / T 2 …”

Excellent red upconversion luminescence in GdLaO3:Er3+/Yb3+/Sc3+ under 980 nm laser excitation

“…In general, for oxide UCL phosphors with low phonon energy, red UCL should come mainly from CR, which has also been discussed in detail in some other studies. [35][36][37][38] The three CR 1, CR 2 and CR 3 processes involve the following transitions: 4 S 3/2 (Er 3+ ) + 2 F 7/2 (Yb 3+ ) -4 I 13/2 (Er 3+ ) + 2 F 5/2 (Yb 3+ ) (CR 1), 4 I 13/2 (Er 3+ ) + 2 F 5/2 (Yb 3+ ) -4 F 9/2 (Er 3+ ) + 2 F 7/2 (Yb 3+ ) (CR 2), and 4 F 7/2 (Er 3+ ) + 4 I 11/2 (Er 3+ ) -4 F 9/2 (Er 3+ ) + 4 F 9/ 2 (Er 3+ ) (CR 3). CR 1 can reduce the populated electron number at 4 S 3/2 , which produces green UCL.…”