Radiation-to-heat conversion efficiency in SrF2:Yb3+/Er3+ upconverting nanoparticles

authors	Balabhadra, S; Debasu, ML; Brites, CDS; Ferreira, RAS; Carlos, LD
nationality	International
journal	OPTICAL MATERIALS
author keywords	Upconverting nanoparticles; Near infrared radiation; Photothermal conversion efficiency
keywords	PHOTOTHERMAL THERAPY; CANCER-CELLS; DRUG-DELIVERY; GOLD NANOCAGES; GRAPHENE OXIDE; NANOCRYSTALS; ABLATION; AGENT; NANOCOMPOSITES; NANORODS
abstract	The photoexcitation of materials results in the production of thermal energy (heat) under laser excitation and is an evolving field of research, prompted by the ever-growing demands in the fields of nanotechnology and nanomedicine. Understanding the radiation-to-heat conversion efficiency is, thus, important for the selection of the more suitable materials for photothermal therapeutic applications. To this regard, laser irradiation at near infrared frequencies are indispensable, offering deeper penetration depths in biological tissues, when compared with visible ones. Here, the molar extinction coefficients of SrF2:Yb3+/Er3+ upconverting nanoparticles with diameters 10 +/- 2 nm and 41 +/- 10 nm were calculated at 980 nm as 2.43 M-1 cm(-1) and 2.40 M-1 cm(-1), respectively. The corresponding photothermal conversion efficiencies are 32.0 +/- 1.0% and 11.5 +/- 0.8%, for the 10 nm and 41 nm diameter upconverting nanoparticles, respectively. The photothermal efficiency values of SrF2:Yb3+/Er3+ nanoparticles permit to prospect their future use as photothermal agents.
publisher	ELSEVIER SCIENCE BV
issn	0925-3467
year published	2018
volume	83
beginning page	1
ending page	6
digital object identifier (doi)	10.1016/j.optmat.2018.05.069
web of science category	Materials Science, Multidisciplinary; Optics
subject category	Materials Science; Optics
unique article identifier	WOS:000440116200001