Multimode high-sensitive optical YVO4:Ln3+ nanothermometers (Ln3+ = Eu3+, Dy3+, Sm3+) using charge transfer band features

Abstract

Accurate thermal sensing with good spatial resolution is currently required in variety of scientific and technological areas. Luminescence nanothermometry has shown competitive superiority for contactless temperature sensing especially at the nanoscale. To broaden use of such thermometers, development of novel sensor type with high sensitivity and resolution is highly demanded. Herein, we report single-phase Ln3+-doped YVO4 nanophosphors synthesized via modified Pechini method as multimode optical thermometers with wide-range temperature probing (299–466 K). The observed temperature-induced red shift of charge transfer band was utilized to provide thermal sensing. Temperature sensing was based on luminescence intensity ratio using emission intensities obtained upon charge transfer band and direct lanthanide excitation, spectral position of charge transfer band and its bandwidth. The suggested probing strategies provided high relative thermal sensitivity (up to 3.09 % K-1) and precise temperature resolution (up to 0.1 K). The obtained results can be useful for design of novel contactless luminescence thermometers.