abstract
We combined the sensing capabilities of Er3+-doped upconverting nanoparticles (UCNPs) with hyperspectral microscopy to construct thermal images on thermally active nanostructures. Here, we studied the heat dissipation of a percolating network of silver nanowires under controlled electric current flow. We quantified the electrothermal action by analyzing the hyperspectral data and constructing 2D maps for the emission intensity, the signal-to-noise ratio, and the thermometric parameter. By studying selected clusters in the network, we concluded that the temperature is quite uniform across the film without any significant thermal gradients. Nonetheless, the thermal evolution was clearly sensed by the UCNPs when the heat dissipation due to the Joule effect was turned on and off, validating the use of this method for studying slow-dynamic thermal processes. Finally, we discuss the accuracy of the thermal readings and the systematic limitations of the proposed method.
keywords
NANOWIRE NETWORKS; MICROSCOPY; LUMINESCENCE
subject category
Physics
authors
Martinez, ED; Brites, CDS; Urbano, RR; Rettori, C; Carlos, LD
our authors
Carlos Brites
Associate Professor
Luís Carlos
Full professorProjects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
Nanoparticles - based 2D thermal bioimaging technologies - NanoTBTech (NanoTBTech)
acknowledgements
This work was supported and performed under the auspices of FAPESP through Grants #2011/19924-2, #2012/04870-7, #2012/05903-6, #2015/21290-2, #2015/21289-4, and #2017/10581-1. E. D. M was the beneficiary of a post-doctoral FAPESP fellowship #2015/23882-4 during part of the development of this work. R. R. U acknowledges CNPq Grant No 309483/2018-2. E. D. M. acknowledges funding from ANPCyT-FONCyT through grants PICT 2017-0307 and PICT Start Up 2017-00017. Research supported by LNNano-Brazilian Nanotechnology National Laboratory, (CNPEM/MCTI) during the use of the electron microscopy open-access facility. This work was also developed within the scope of the project CICECO -Aveiro Institute of Materials, UIDB/50011/2020, financed by Portuguese funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. Financial support from the European Union's Horizon 2020 FET Open programme under grant agreement no. 801305 is also acknowledged. Financial support from FCT (NANOHEATCONTROL -POCI-01-0145-FEDER-031469) is acknowledged. This work was initiated at IFGW-UNICAMP, Brazil, and finished at the current affiliation of the corresponding author.