Dual-Mode Optical Thermometry Design in Lu₃Al₅O₁₂:Ce³⁺/Mn⁴⁺ Phosphor

Abstract

There is a challenge for noncontact temperature-sensing techniques and the related materials, in which a highly reliable contactless thermometer probe with low cost and high sensitivity is in demand. Here, the Lu3Al5O12:Ce3+/Mn4+ phosphor has been designed and prepared for the high-performance fluorescence temperature-sensing application in a novel one-pot, self-redox, solid-state process. Benefiting from the different electron–lattice/phonon interactions of Ce3+ and Mn4+, two distinguishable emission peaks with significantly different temperature responses originating from Ce3+ and Mn4+ are realized. Applying the fluorescence intensity ratio of Mn4+ versus Ce3+ and the decay lifetime of Mn4+ emission as the temperature readout, a dual-mode optical temperature-sensing mechanism was proposed and studied in the temperature range of 100–350 K. The maximum relative sensitivities (S r) are derived as 4.37 and 3.22% K–1 respectively, as well as a large chromaticity shift visible to naked eyes (ΔE = 153 × 10–3 in 100–350 K) is observed. This is the first report of a Ce3+,Mn4+ co-doped dual-emitting phosphor, and its unique optical thermometric features demonstrate the high potential of Lu3Al5O12:Ce3+/Mn4+ as an accurate and reliable thermometer probe candidate.

Al2O3 co-doped with Cr3+ and Mn4+, a dual-emitter probe for multimodal non-contact luminescence thermometry

“…A further performance enhancement of luminescence probes can be achieved by using a pair of emitters. 33 Combinations of different rare earth ions [34][35][36][37] as well as pairing rare-earth with transition metal ions [38][39][40][41][42] have been explored extensively and it has been shown that having two emitters in the same crystal enables a sensitivity enhancement and permits operation of the sensor over an extended temperature range. It is therefore important to assess this enhancement that a material with dual-emitters, multimodal sensor of temperature can bring, the topic of this feasibility study.…”

Thermally boosted upconversion and downshifting luminescence in Sc2(MoO4)3:Yb/Er with two-dimensional negative thermal expansion

“…6d). The optimal Sr value of SMO:Yb/Er was observed to be an order of magnitude higher than that of other majority LLTs 39,[40][41][42][43][44] .…”

mOptical Sensing for the Internet of Things: A Smartphone‐Controlled Platform for Temperature Monitoring

“…[ 42 ] Figure a (and Table S2, Supporting Information) shows examples of the largest S r values ( S m ) reported for ratiometric (hollow symbols) luminescent thermometers with an operating range compatible with m Optical sensing and for smartphone‐based luminescence thermometry (solid symbols). [ 46,55,59,66–89 ] The S r values for primary luminescent thermometers are shown in Figure 3b. [ 43,53,58–64 ] Noticeable, only one example refers to smartphone‐based luminescence thermometry, and presents the largest S r value.…”