X-ray-charged bright persistent luminescence in NaYF4:Ln3+@NaYF4 nanoparticles for multidimensional optical information storage

Abstract

NaYF4:Ln3+, due to its outstanding upconversion characteristics, has become one of the most important luminescent nanomaterials in biological imaging, optical information storage, and anticounterfeiting applications. However, the large specific surface area of NaYF4:Ln3+ nanoparticles generally leads to serious nonradiative transitions, which may greatly hinder the discovery of new optical functionality with promising applications. In this paper, we report that monodispersed nanoscale NaYF4:Ln3+, unexpectedly, can also be an excellent persistent luminescent (PersL) material. The NaYF4:Ln3+ nanoparticles with surface-passivated core–shell structures exhibit intense X-ray-charged PersL and narrow-band emissions tunable from 480 to 1060 nm. A mechanism for PersL in NaYF4:Ln3+ is proposed by means of thermoluminescence measurements and host-referred binding energy (HRBE) scheme, which suggests that some lanthanide ions (such as Tb) may also act as effective electron traps to achieve intense PersL. The uniform and spherical NaYF4:Ln3+ nanoparticles are dispersible in solvents, thus enabling many applications that are not accessible for traditional PersL phosphors. A new 3-dimensional (2 dimensions of planar space and 1 dimension of wavelength) optical information-storage application is demonstrated by inkjet-printing multicolor PersL nanoparticles. The multicolor persistent luminescence, as an emerging and promising emissive mode in NaYF4:Ln3+, will provide great opportunities for nanomaterials to be applied to a wider range of fields.

Thermal enhancement of upconversion in lanthanide-doped Gd2Ti2O7 crystals via fast evaporation in a sol–gel procedure

“…Lanthanide doped luminescent materials exhibit tunable emission wavelengths, superior photostability, large anti-Stokes and long excited state lifetimes, 1–5 and have attracted enormous attention in many emerging applications, such as background-free biosensing, 6–10 full-colour display, 11,12 optical multiplexing, 13–15 information storage and security anti-counterfeiting. 16–22 The luminescence intensity, which is one of the major performance indexes, generally decreases evidently at an elevated temperature owing to the increased multi-phonon assisted non-radiative relaxation possibility. 23–25 This thermal quenching effect greatly restricts the application of these luminescent materials; 26 thus, it is of significance to develop new strategies to combat thermal quenching.…”

Broadband multimodal emission in Sb-doped CaZnOS-layered semiconductors

“…5d shows a real photograph of XIL for the sample with X-ray on (Open) and off (Close, taken 10 s after the X-ray was turned off), showing a light orange luminescence and a long afterglow phosphorescence characteristic (Video S4). If the particles can be made small enough in the future, they are expected to have applications in biological and chip monitoring [60][61][62][63][64][65].…”

Designing Next Generation of Persistent Luminescence: Recent Advances in Uniform Persistent Luminescence Nanoparticles

“…Moreover, as an efficient host matrix for upconversion luminescence, the coating of the NaYF 4 shell by the colloidal synthesis can also introduce photon-upconverting properties into the CaF 2 :Dy@ NaYF 4 PLNPs, making the PLNPs optically multifunctional. Independently, a recent series of works on colloidal synthesis, especially with respect to the production of lanthanide-doped uniform PLNPs, [3,4,39] have significantly encouraged the great interest in PLNP research.…”