High-Quantum-Yield Upconverting Er3+/Yb3+-Organic-Inorganic Hybrid Dual Coatings for Real-Time Temperature Sensing and Photothermal Conversion

authors	Caixeta, FJ; Bastos, ARN; Botas, AMP; Rosa, LS; Souza, VS; Borges, FH; Neto, ANC; Ferrier, A; Goldner, P; Carlos, LD; Goncalves, RR; Ferreira, RAS
nationality	International
journal	JOURNAL OF PHYSICAL CHEMISTRY C
keywords	UP-CONVERSION; CANCER-CELLS; GRAPHENE OXIDE; EFFICIENT ABLATION; ENERGY-TRANSFER; GOLD NANOCAGES; DRUG-DELIVERY; WAVE-GUIDES; NANOPARTICLES; NANOCRYSTALS
abstract	Flexible coatings with dual capabilities for remote real-time temperature sensing and photothermal conversion have a huge potential in the field of advanced thermal actuated optoelectronic applications. In this work, we demonstrated that plastic free-standing films of Er3+/Yb3+-codoped GeO2-Ta2O5 particles dispersed in poly(methyl methacrylate) (PMMA) having intriguing upconversion high absolute emission quantum yield (similar to 0.1452, excited at 980 nm, 760 W.cm(-2)) can simultaneously operate as photothermal converters and real-time primary thermometers. The emission of the films was studied at the microscale, revealing emission homogeneity detected through surface hyperspectral microscopy. One factor that contributes to the unusually high absolute emission quantum yield, when compared with other oxides-based materials, is the high occurrence (probability) of the shortest Yb-Er distances obtained when the YbTaO4 phase is formed. This, as demonstrated by computational simulations of doping processes, favors the Yb-to-Er energy transfer rates, enhancing the population of the Er3+ emitting levels. Besides, the films combined a relative thermal sensitivity of similar to 1.1% K-1 (at 300 K) with a temperature uncertainty of similar to 0.7 K and a maximum photothermal efficiency of similar to 44%, which permits the prospect of using this material as a coating with photothermal and thermometer functions. Moreover, as an added benefit, the thermal resistance of the composite in PMMA was estimated, yielding a maximum value of 760 +/- 8 K.W-1. This is the first example of an active coating for photothermal conversion with the simultaneous ability to remotely sense temperature that can be explored in NIR-pumped free-space telecommunications without the need of additional optoelectronics devices.
publisher	AMER CHEMICAL SOC
issn	1932-7447
isbn	1932-7455
year published	2020
volume	124
issue	37
beginning page	19892
ending page	19903
digital object identifier (doi)	10.1021/acs.jpcc.0c03874
web of science category	Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary
subject category	Chemistry; Science & Technology - Other Topics; Materials Science
unique article identifier	WOS:000574908200003