Unravelling phase and morphology evolution of NaYbF₄ upconversion nanoparticles via modulating reaction parameters

Abstract

The applications of upconversion nanoparticles in biodetection, bioimaging, and lighting have greatly fuelled a growing demand for enhancing their brightness. The brightness of upconversion nanoparticles is fundamentally limited by the...

Unraveling the Growth Process of Core–Shell Structured Upconversion Nanoparticles: Implications for Color Tuning of Upconversion Luminescence

“…It should be noted that the high-temperature coprecipitation method was used to synthesize core–shell UCNPs, which was initially proposed by Li et al As a well-established method, the procedures to synthesize core–shell UCNPs are typically standardized, which generally include preparation of core particle solution, injection of shell precursor solution, and heat-up of the reaction mixture at a high temperature (around 300 °C) for over 1 h. Nevertheless, the synthesis of core–shell UCNPs can still be readily optimized by tuning several significant parameters, such as selection of raw materials, injection rate, reaction temperature, , and reaction time, that could help to optimize the synthesis of core–shell nanoparticles.…”

Synthesis of lanthanide-based scintillator@MOF nanocomposites for X-ray-induced photodynamic therapy

“…The lanthanide-based nanoparticles were synthesized through high-temperature coprecipitation in a binary solvent mixture of OA and ODE. 28 In a typical procedure, 4 mL aqueous solution containing 0.56 mmol Gd(Ac) 3 and 0.24 mmol Tb(Ac) 3 was mixed with 8 mL OA and 12 mL ODE in a 100 mL three-neck round-bottom flask. The mixture was heated at 115 °C for 60 min to remove water and then heated at 155 °C for 30 min under a nitrogen atmosphere to obtain a Ln-OA chelator, followed by cooling to room temperature.…”

A low-temperature self-flux route to prepare hexagonal rare earth fluorides and manipulation of upconversion luminescence in rodlike NaYbF4:Tm3+/Fe3+ crystals

“…In the past several decades, considerable attention has been paid to ytterbium-based fluoride upconversion (UC) materials (including α-NaYbF 4 , β-NaYbF 4 , LiYbF 4 and KYb 2 F 7 ) with high levels of the most efficient sensitizer Yb 3+ due to some inherent outstanding physicochemical characteristics, including strong absorption for maximizing the utilization of near-infrared (NIR) pump photons owing to large absorption cross-sections (10 −20 cm −2 at ∼980 nm), only one excited manifold resulting in a lack of cross relaxation (CRs) between Yb 3+ ions, and its energy level transition being resonating well with the f-f transitions of the general rare earth activators (Er 3+ , Tm 3+ and Ho 3+ ), and thus generating efficient UC emissions. [1][2][3][4][5][6][7][8][9] As a consequence, ytterbium-based fluorides for constructing UC materials are believed to be promising substitutes for their distinctive yttrium (Y)-, lanthanum (La)-, gadolinium (Gd)-and lutetium (Lu)-based counterparts and to hold tremendous potential for applications in energy harvesting and conversion, sensors, and as biological labels and computed tomography contrast agents for multimodal bio-imaging. [1][2][3][4][5][6][7][8][9][10][11][12][13] Recently, Fe 3+ doping has attracted increasing interest based on the following aspects.…”

“…[1][2][3][4][5][6][7][8][9] As a consequence, ytterbium-based fluorides for constructing UC materials are believed to be promising substitutes for their distinctive yttrium (Y)-, lanthanum (La)-, gadolinium (Gd)-and lutetium (Lu)-based counterparts and to hold tremendous potential for applications in energy harvesting and conversion, sensors, and as biological labels and computed tomography contrast agents for multimodal bio-imaging. [1][2][3][4][5][6][7][8][9][10][11][12][13] Recently, Fe 3+ doping has attracted increasing interest based on the following aspects. [14][15][16][17][18][19][20][21][22] First and foremost, Fe 3+ is a low-cost, nontoxic and harmless trivalent non-rare-earth metal ion, which gives it considerable appeal in a great number of areas including energy storage, quantum information processing, classic data storage, magnetic resonance imaging and spin-controlled reactions.…”

“…1–9 As a consequence, ytterbium-based fluorides for constructing UC materials are believed to be promising substitutes for their distinctive yttrium (Y)-, lanthanum (La)-, gadolinium (Gd)- and lutetium (Lu)-based counterparts and to hold tremendous potential for applications in energy harvesting and conversion, sensors, and as biological labels and computed tomography contrast agents for multimodal bio-imaging. 1–13…”