Er³⁺-to-Yb³⁺ and Pr³⁺-to-Yb³⁺ energy transfer for highly efficient near-infrared cryogenic optical temperature sensing

Abstract

Nanothermometers based on Er3+-to-Yb3+ and Pr3+-to-Yb3+ energy transfer show very high performance in the near-infrared region in the cryogenic temperature regime.

Developing Luminescent Ratiometric Thermometers Based on a Covalent Organic Framework (COF)

“…We observed no decrease in the Tb 3+ decay times with increasing temperature,aswould be expected if there was aTb 3+ -to-Eu 3+ energy transfer in this material. [16,44] TheT b 3+ decay times slightly fluctuate throughout the temperature range,b ut this can be caused by inaccuracies in the fitting of the decay curves.The decay times of Eu 3+ remain constant between 10-360 K. Finally,t oe valuate the performance of this type of mixed Eu 3+ ,T b 3+ TpBpy thermometer,t hree runs of cycle tests were performed for 5 to confirm the stability of the material (Figure 5c). Ther epeatability of the thermometer was calculated to be 97.5 %[ determined by employing Equation (S4)].…”

“…It also allows avoiding issues with alignment and optoelectronic drifts of the excitation source and detectors.M any currently published ratiometric temperature sensors are based on trivalent lanthanide ions (Ln 3+ ). [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Ln 3+ -based materials are recognized for their intriguing luminescence properties, namely narrow line-like emission ranging from the ultraviolet to the visible and near-infrared regions,r elatively long luminescence decay times,a nd high quantum-yield values. [17,18] These properties can be ascribed to the very well shielded 4f-4ft ransitions.O ne major downside of Ln 3+ ions are their low absorption coefficients,b ut this can be easily overcome by tailoring hybrid organic-inorganic materials, where the metal ions are excited through as o-called "antenna" ligand.…”

Cryogenic Luminescent Ratiometric Thermometers Based on Tetragonal Na[LnSiO4]·xNaOH (Ln = Gd, Tb, Eu; x ≈ 0.2)

“…At higher temperature, the 3 and 4 relative sensitivity is small, reaching 0.16 and 0.12 %K –1 at 300 K, respectively. Concerning maximum relative sensitivity ( S m ), 4 is only outperformed by the cryogenic ( T < 100 K) luminescent ratiometric thermometers Sr 2 GeO 4 :Pr 3+ , Sr 2 (Ge,Si)O 4 :Pr 3+ , LaF 3 :Yb 3+ ,Er 3+ , MoO 3 :Tb,Eu, and two Ln‐bearing metal‐organic frameworks, (Tableà). Importantly, 4 outperforms the only two Ln‐silicate cryogenic ratiometric thermometers reported so far, Na[(Gd 0.8 Eu 0.1 Tb 0.1 )SiO 4 ][16c] and Na 2 K[(Lu 0.75 Yb 0.20 Er 0.05 ) 3 Si 6 O 18 ].…”

“…[6d] Notable exceptions are the Ln‐bearing MOFs, Tb 0.95 Eu 0.05 HL (H4L = 5‐hydroxy‐1,2,4‐benzenetricarboxylic acid) and Eu 0.02 Gd 0.98 (dsb) (H3dsb = 3,5‐disulfobenzoate), that present maximum S r of 31.0 %K –1 at 4 K, and 7.14 %K –1 at 65 K, respectively , . Recently, four inorganic Ln‐materials with S r > 6 %K –1 have also been reported, namely Sr 2 GeO 4 :Pr 3+ ( S r 9.0 %K –1 at 22 K), Sr 2 (Ge,Si)O 4 :Pr 3+ (9.2 %K –1 at 65 K), LaF 3 :2.96 % Er 3+ ,1.57 % Yb 3+ (6.6 %K –1 at 15 K), and MoO 3 :Tb,Eu (9.2 %K –1 at 15 K) …”

Fe3+-codoped ultra-small NaGdF4:Nd3+ nanophosphors: enhanced near-infrared luminescence, reduced particle size and bioimaging applications

“…Lanthanide (Ln 3+ )-doped uoride nanoparticles (NPs) simultaneously exhibiting small particle size and strong photoluminescence (PL) intensity are in high demand for their potential application in bioimaging. [1][2][3][4][5][6][7][8] In particular, the trivalent neodymium (Nd 3+ ) doped NPs show superior optical properties in luminescent bioimaging as both their excitation and emission can be located at the near-infrared (NIR) region, which provides high penetration depth and signal-to-noise ratio in biological specimens. [9][10][11][12] For minimizing the potential interference in cellular systems and favoring the easier excretion from the body, ultra-small NPs with particle sizes of less than 6 nm are also necessary.…”