Er3+-Yb3+ doped vanadate nanocrystals: A highly sensitive thermographic phosphor and its optical nanoheater behavior

Abstract

Optical temperature sensors play a vital role in biomedical and therapeutic applications due to their reliable and unique detection sensitivity. Internal self-heating in Er3+/Yb3+ doped yttrium vanadate particles is observed on optical excitation at 980 nm wavelength of a diode laser. Temperature sensing performance is investigated by exploiting the temperature dependent fluorescence intensity ratio (FIR) of two emission bands (H-2(11/2)/S-4(3/2)-> I-4(15/2)) of Er3+ ion. The calculated sensor sensitivity, 0.01169 K-1 at 380 K, is found the highest among the reported results for inorganic nanosensors. The temperature of the nanocrystalline sample particles is found to increase by a large value (315-460 K) within a short interval of excitation pump power (13.18-50.45W cm(-2)). This achievement suggests potential use of the present material as an optical nanoheater for hyper-thermal treatment. (C) 2014 Elsevier B.V. All rights reserved.