Editors: | F. Kongoli, F. Marquis, S. Kalogirou, B. Raveau, A. Tressaud, H. Kageyama, A. Varez, R. Martins. |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2022 |
Pages: | 154 pages |
ISBN: | 978-1-989820-34-6 (CD) |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
Temperature plays an essential role in biological systems, affecting a variety of their properties. For example, the cell division rate, and consequently tissue growth, are both critically influenced by temperature. The precise measurement of temperature is needed for both early diagnosis and treatment of malignant diseases. Nowadays, luminescence thermometry is considered to be a promising tool for non-invasive bio-thermal-imaging [1]. For such use, the biocompatible and near-infrared-emitting nanoparticles showing the strong temperature dependence of emission are urgently needed. Working within a near-infrared spectral region (the first and second biological windows) overcomes small light penetration lengths occurring with visible-emitting nanoparticles since in biological windows the extinction coefficient of tissues is low due to a simultaneous reduction in both tissue scattering and absorption coefficients [2]. Herein, well-known Yb3+,Er3+-doped yttrium aluminium garnet (YAG) nanopowder is prepared by the combustion method. The cubic structure of the material was confirmed by X-ray diffraction measurements, while UV-Vis-NIR diffuse reflectance showed typical Yb3+/Er3+ absorption bands. We have investigated the temperature dependence of near-infrared emission of the phosphor aiming to compare the thermometric performances of two different read-outs: i) changes in the intensities of emission bands and ii) changes in the emission bands position and bandwidths. Temperature dependant near-infrared emission spectra were measured in the 1000-1550 nm spectral range upon 980 nm excitation. Following combinations were investigated: i) luminescence intensity ratio of 1470/1530 nm Er3+ emission lines; ii) luminescence intensity ratio of 1030 nm Yb3+ and two Er3+ emission lines (1470 and 1530 nm); iii) Yb3+ emission band position and iv) Yb3+ emission bandwidth (FWHM). Among investigated read-out approaches, the most important figures of merit, absolute and relative sensitivities, and temperature resolutions have been calculated and compared.
[1] M. D. Dramićanin, Luminescence Thermometry, Imprint Woodhead Publishing, Elsevier Science: Cambridge, United Kingdom (2018) [2] B. del Rosal, A. Pérez-Delgado, M. Misiak, A. Bednarkiewicz, A. S. Vanetsev, Y. Orlovskii, D. J. Jovanović, M. D. Dramićanin, U. Rocha, K. Upendra Kumar, C. Jacinto, E. Navarro, E. Martín Rodríguez, M. Pedroni, A. Speghini, G. A. Hirata, I. R. Martín, D. Jaque, J. Appl. Phys., 118 (2015) 143104 (11p).