Solvothermal synthesis and upconversion properties of about 10 nm orthorhombic LuF3: Yb3+, Er3+ rectangular nanocrystals

White and red emitting LaF 3 nanocrystals doped with Eu 2+ and Eu 3+ ions: Spectroscopic and magnetic studies

“…Thanks to the effect of admixture with adequately chosen lanthanide (Ln 3þ ) ions, the materials based on RE fluorides can be an alternative to the currently used phosphors [9]. REF 3 can be used in optoelectronics for construction of optic fibres and amplifiers of optical signals and are promising materials for lasers and in some areas of medicine, especially in bioimaging [10e13]. Particularly because of their high chemical stability, chemical neutrality and low cytotoxicity, REF 3 are an attractive alternative for the quantum dots intensely studied for the use as luminescent markers [14e17].…”

“…REF 3 can be used in optoelectronics for construction of optic fibres and amplifiers of optical signals and are promising materials for lasers and in some areas of medicine, especially in bioimaging [10e13]. Particularly because of their high chemical stability, chemical neutrality and low cytotoxicity, REF 3 are an attractive alternative for the quantum dots intensely studied for the use as luminescent markers [14e17]. For bio-related applications the surface of REF 3 nanoparticles is coated with specific modifiers that can act as chemically active receptors and increase the stability of water colloids [14,18e20].…”

“…Particularly because of their high chemical stability, chemical neutrality and low cytotoxicity, REF 3 are an attractive alternative for the quantum dots intensely studied for the use as luminescent markers [14e17]. For bio-related applications the surface of REF 3 nanoparticles is coated with specific modifiers that can act as chemically active receptors and increase the stability of water colloids [14,18e20].…”

“…The low energy of crystal lattice definitely contributes to the high energetic effectiveness of REF 3 as matrices ideal for luminescent Ln 3þ ions, e.g. in LaF 3 the phonon energy is only of 350 cm À1 [21], which means that materials doped with Eu 3þ and Tb 3þ exhibit luminescence with high quantum yield [22].…”

“…Poor water solubility of fluorides permits their synthesis at room temperature via the precipitation by e.g. NaF or NH 4 F. Many methods for the synthesis of REF 3 have been proposed, among others precipitation in the presence of surfactants or in microemulsions [23,24]. The hydrothermal method and other methods involving it have also been rather widely used [7].…”