Synthesis and optical properties of infrared-emitting YF3:Nd nanoparticles

Abstract

Nd 3 + -doped YF3 (YF3:Nd) nanoparticles with a size of ∼20 nm were synthesized by solvothermal decomposition of yttrium and neodymium trifluoroacetate precursors in oleylamine. Using the 4f-energy matrix diagonalization procedure various interaction parameters: Slater–Condon (F2, F4, and F6), spin-orbit (ξ), two body interaction (α, β, and γ), Judd parameters (T2, T3, T4, T6, T7, and T8), spin-other-orbit parameters (M0, M2, and M4) and electrostatically correlated spin-orbit interaction parameters (P2, P4, and P6), and the crystal-field parameters (Bqk) were evaluated. The potential of YF3:Nd as a laser host for 1052 nm emission was evaluated by quantitative analysis of the absorption, emission spectra, and fluorescence decay characteristics. Judd–Ofelt parametrization was employed to compute the radiative spectral parameters such as radiative transition probabilities, fluorescence branching ratios, stimulated emission cross sections, and quantum efficiencies of the observed bands in the fluorescence spectrum. Using the measured radiative properties, 75% quantum efficiency was obtained for the principal emission band at 1052 nm when the Nd dopant concentration was 0.25 mol %, with an emission cross section of 0.74×10−20 cm2. Analysis of the energy transfer kinetics showed that at low dopant concentrations of 0.25 mol % dipole-dipole interactions were dominant, whereas energy migration was the leading process at higher dopant concentrations. Quenching by OH impurities was found to be within the limit of optimum amplifier performance where multiphonon relaxation losses were negligible. Preliminary optical characterization showed that these nanocrystalline materials can be potentially used as optical amplifiers and in applications like infrared imaging, security and authentication.

Radiative Lifetime Modification of LaF3:Nd Nanoparticles Embedded in 3D Silicon Photonic Crystals

“…It is known that the Nd 3 + quantum effi ciency increases as the Nd doping concentration is decreased. [ 33 ] We fi nd that 0.5% Nd doped LaF 3 is optimal taking into consideration both quantum yield and brightness.…”

Rare earth nanoprobes for functional biomolecular imaging and theranostics

“…The solvothermal synthesis method has been used to grow various rare-earth doped particles with controlled micron- to nano-sizes and morphologies by adjusting the reaction parameters, like precursor concentration, time and solvent. 29, 37, 39, 41, 42, 45, 47, 49–52 For example, the thermal decomposition of rare earth trifluoroacetate precursors in solvents such as oleic acid or oleylamine under temperatures 250–350°C is commonly used to synthesize crystalline monodisperse REs of tailored size. 42, 53, 45 …”

“…For example, the hydrocarbon (-CH 2 ) and hydroxyl (-OH) groups present on surfactants used during synthesis can deactivate surface rare-earth ions on REs and result in emission quenching. 41 We have previously investigated the effects various surfactant formulations have on RE emission using micron-sized particles. NaYF 4 :Yb-Er were synthesized using the hydrothermal method and subsequently modified with low concentrations of different surfactants.…”

Surface-Modified Shortwave-Infrared-Emitting Nanophotonic Reporters for Gene-Therapy Applications

“…These probes emit shortwave infrared (SWIR) light upon excitation by NIR light (980 nm), which has several advantageous properties, including deeper penetration through biological tissue, for biological imaging. 17–19 Additionally, the absence of excitation–emission band overlap and elimination of tissue autofluorescence produces significantly improved signal-to-noise ratios. We have previously shown that RENPs can be rendered biologically safe by encapsulation in albumin nanocomposites 15 and can be targeted for the detection of micrometastatic lesions in multiple organs.…”