Improving performance of luminescent nanothermometers based on non-thermally and thermally coupled levels of lanthanides by modulating laser power

Abstract

This work sheds the light on the pump power impact on the performance of luminescent thermometers, which is often underestimated by researchers. The up-converting, inorganic nanoluminophore YVO4:Yb3+, Er3+ (nanothermometer) was...

Ratiometric Upconversion Temperature Sensor Based on Cellulose Fibers Modified with Yttrium Fluoride Nanoparticles

“…In the case of measurement performed with the use of knitted fabric, the laser beam was focused to an approximately 4 mm size beam spot, and the applied power was adjusted to 0.5 W, which corresponds to a power density of about 4 W/cm 2 . The power density in the applied range (from ~4 to 360 W/cm 2 ) enables measurements without heating of the sample and does not influence the temperature sensitivity of the thermometer (because the laser power does not influence the LIR of the bands that are associated with TCLs [ 27 ]).…”

“…YF 3 NPs doped with 20 mol% Yb 3+ and 2 mol% Er 3+ were synthesized following our previously reported procedure [ 27 ]. To prepare 0.5 g of product, 4.75 mL of 0.5 M YCl 3 and 1.22 mL of 0.5 M YbCl 3 were mixed with 1.22 mL of 0.05 M ErCl 3 aqueous solutions and filled up to 25 mL with water.…”

“…Among the various optical methods used to determine temperature, luminescence thermometry appears to be a very promising alternative [ 23 , 24 , 25 , 26 , 27 , 28 ]. Temperature sensors based on the phenomenon of luminescence exploit temperature-induced changes in the spectroscopic properties of phosphors, for instance: changes in the intensity or width of emission bands, the appearance of new bands in the emission spectrum, shortening of emission lifetimes, changes in the luminescence (fluorescence) intensity ratio—LIR (FIR) of two bands, spectral shifts in absorption/emission bands, and different efficiency of energy and charge transfer processes [ 23 , 24 ].…”

Synergistic luminescent thermometer using co-doped Ca2GdSbO6:Mn4+/(Eu3+ or Sm3+) phosphors

“…For example, high thermal sensitivity responses can be obtained using emissions from the non-thermally coupled energy level of trivalent lanthanide (Ln 3+ ) ions. 27 Recently, the most popular one is to exploit the high sensitivity of the emission intensity of transition metal (TM) ions to temperature variations and the small temperature dependence of Ln 3+ emission. As to the emissions of TM ions, high temperature sensitivity can be achieved through the strong quenching from inherent defects.…”

Generation of Pure Green Up-Conversion Luminescence in Er3+ Doped and Yb3+-Er3+ Co-Doped YVO4 Nanomaterials under 785 and 975 nm Excitation

“…The discussed materials, based on vanadate matrices are also thermally very stable, [59][60][61], and therefore they are used as thermochromic phosphors, scintillators or optically active components of lasers [62] as well as contact-less temperature sensors [63,64], optical high pressure and vacuum sensors [29] and for fingerprint detection [27].…”