Wide-range ratiometric upconversion luminescence thermometry based on non-thermally coupled levels of Er in high-temperature cubic phase NaYF₄: Yb, Er

Temperature-Independent Lifetime and Thermometer Operated in a Biological Window of Upconverting NaErF4 Nanocrystals

“…This temperature-independent variation might be the consequence of the lattice expansion with heating, which can be proven by the blue-shift of the XRD peaks with increasing temperature [Figure 1b] and is in good agreement with the observations elsewhere [38][39][40]. As mentioned above, CR processes are dominant for Er 3+ UC lifetimes.…”

Highly Sensitive Upconverting Nanoplatform for Luminescent Thermometry from Ambient to Cryogenic Temperature

“…In the absence of G 1 , the emission is nearly bimodal, and color variation is directly attributed to the change in relative contributions of G 2 and R from 140 K to 4 K. We propose that a colorimetric temperature sensing scale can be defined as long as the bimodality of the emission is maintained and the ratios of carrier population in thermally uncoupled bands change monotonically with temperature within the range of interest. Reports by Sun et al [30] and, more recently, by Janjua et al [31] qualitatively show the realization of such thermometers in the high-temperature regime. Apart from a qualitative argument, we provide a precise quantitative measure of both the temperature and the sensitivity of the colorimetric probe in terms of perceptual color fidelity metric (PCFM).…”

Ratiometric upconversion luminescence nanoprobes from construction to sensing, imaging, and phototherapeutics

“…As summarized in Table 1, previous studies have largely reported various types of ratiometric UCL nanoprobes for temperature sensing. [168][169][170][171][172][173][174][175][176]193,194 Most of the nanoprobe systems consist of lanthanide-doped UCNPs, other upconverting luminescent inorganic materials, 29,36,40,43,45,47,48,54,[56][57][58][59][60][61]65,[73][74][75][76] and the derivatives with functional modifications, including the core@shell, 37,38,41,68,72,78,79 hollow/porous, 38 complexes, 46,49,51 hybrid, 32,52 mixture, 33,35 assembly, 34,55 or engineering structures.…”

“…Different types of the UCL ratiometric nanoprobes summarized in table format Ti 3 O 12 :Yb 3+ /Ho 3+ ,83 Gd 2 Mo 4 O 15 :Yb 3+ /Ho 3+ ,65 Gd 4.67 Si 3 O 13 :Eu 3+ /Yb 3+ /Tm 3+ ,58 GdVO 4 :Er 3+ ,84 Gd 2 (WO 4 ) 3 : Ho 3+ /Tm 3+ /Yb 3+ ,[73][74][75] MgMoO 4 :Er 3+ /Yb 3+ ,59 NaNbO 3 :Tm 3+ ,30 NaYF 4 :Yb 3+ /Er 3+ ,47,61,69 Y 2−x MoO 6 :xEr 3+ , 71 Y 2 O 3 :Er 3+ /Yb 3+ , 76 YVO 4 :Yb 3+ /Tm 3+ , 48 etc.…”