Open AccessDemonstration of Temperature Dependent Energy Migration in Dual-Mode YVO4: Ho3+/Yb3+ Nanocrystals for Low Temperature Thermometry
Author(s) -
Manoj Kumar Mahata,
Tristan Koppe,
Kaushal Kumar,
H. Hofsäß,
U. Vetter
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep36342
Subject(s) - vanadate , luminescence , materials science , photon upconversion , radiative transfer , thermalisation , spectroscopy , hydrothermal circulation , nanocrystal , analytical chemistry (journal) , chemical physics , nanotechnology , atomic physics , chemistry , optoelectronics , optics , chemical engineering , physics , quantum mechanics , chromatography , metallurgy , engineering
A dual mode rare-earth based vanadate material (YVO 4 : Ho 3+ /Yb 3+ ), prepared through ethylene glycol assisted hydrothermal method, demonstrating both downconversion and upconversion, along with systematic investigation of the luminescence spectroscopy within 12–300 K is presented herein. The energy transfer processes have been explored via steady-state and time-resolved spectroscopic measurements and explained in terms of rate equation description and temporal evolution below room temperature. The maximum time for energy migration from host to rare earth (Ho 3+ ) increases (0.157 μs to 0.514 μs) with the material’s temperature decreasing from 300 K to 12 K. The mechanism responsible for variation of the transients’ character is discussed through thermalization and non-radiative transitions in the system. More significantly, the temperature of the nanocrystals was determined using not only the thermally equilibrated radiative intra-4f transitions of Ho 3+ but also the decay time and rise time of vanadate and Ho 3+ energy levels. Our studies show that the material is highly suitable for temperature sensing below room temperature. The maximum relative sensor sensitivity using the rise time of Ho 3+ energy level ( 5 F 4 / 5 S 2 ) is 1.35% K −1 , which is the highest among the known sensitivities for luminescence based thermal probes.