abstract
The growing demand aiming non-invasive diagnosis techniques applications has become an emerging field for developing more efficient bioprobes working in the near infrared (NIR) biological windows. In this work, we propose Er3+/Yb3+ co-doped yttrium niobate as a multifunctional material synthesized via sol-gel method. We study its NIR emission under UV excitation (down-shifting) and NIR-to-visible upconversion (UC) emission and exploit this material as a luminescent thermometer. X-ray diffraction analysis points out the formation of cubic Y3NbO7 crystalline phase after annealing at 1100 degrees C. Intense and narrow 1.5 mu m emission (FWHM ~24 nm) with Er3+ 4I13/2 lifetime value of ca. 5.5 ms are observed under excitation in the host absorption band (276 nm), due to down-shifting process. Down-shifting and upconversion quantum yields (QY) with excitation at 980 nm were reported for the first time for Y3NbO7 material with values of ca. 18% and ca. 0.0020% in the NIR and visible ranges, respectively. Y3NbO7 is a luminescent primary thermometer with maximum relative thermal sensitivity of 1.31 +/- 0.06% K-1, temperature uncertainty of 0.31 K, and repeatability of 99.6%. Furthermore, the relatively high QY values in NIR and UC emission, comparable to fluorides and higher than other oxides, make Er3+/Yb3+ co-doped yttrium niobate an interesting multifunctional probe aiming for biological applications.
keywords
RARE-EARTH NIOBATES; TEMPERATURE SENSING PERFORMANCE; X-RAY-DIFFRACTION; SPECTROSCOPIC PROPERTIES; PHOTOLUMINESCENCE PROPERTIES; MAGNETIC-PROPERTIES; ENERGY-TRANSFER; PROTON CONDUCTION; LN(3)NBO(7) LN; LANTHANIDE
subject category
Optics
authors
Borges, FH; Martins, JC; Caixeta, FJ; Carlos, LD; Ferreira, RAS; Goncalves, RR
our authors
Luís Carlos
Full professor
Maria Rute de Amorim e Sá Ferreira André
Full professoracknowledgements
This work was supported by the Brazilian funding agencies Fapesp (grant number 2017/11301-2 and 2020/05319-9, and the scholarships processes numbers 2017/10424-3, 2018/04587-0, and 2020/00277-6) , CNPq (grant number 303110/2019-8) and CAPES; the CICECO-Aveiro Institute of Materials project, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement; and by FCT (grant number SFRH/BD/139710/2018) .