Future prospects of fluoride based upconversion nanoparticles for emerging applications in biomedical and energy harvesting

Abstract

Rare earth doped/codoped phosphors have been extensively studied for different types of applications based on their intense luminescence features. For this, researchers have tried to choose the inorganic host matrices having both a low phonon cut-off frequency and a high refractive index. Many articles have been published on oxide based phosphor materials, but due to their high cut-off phonon frequency, use of these materials is restricted for optical based applications. This is why additional research has been carried out on fluoride based host materials because of their low phonon frequencies, low composition degradation, and high quantum efficiency. In this paper, the authors review the rare earth fluoride based host nano-and micromaterials for different applications and discuss possible mechanisms.

Upconversion photoluminescence of Ho3+-Yb3+ doped barium titanate nanocrystallites: Optical tools for structural phase detection and temperature probing

“…On the other hand, upconversion luminescence is an optical non-linear anti-Stokes process, which features conversion of low energy photons into high energy by utilizing the quantum mechanically forbidden 4f → 4f optical transitions of R 3+ ions while doped in crystallite host materials [24][25][26][27] . Over the past decade, researchers have shown extensive range of advanced applications of upconversion nanoparticles, spanning from background noise-free biological imaging, theranostics, drug-delivery to photo-voltaic devices, and photochemical reactions [28][29][30][31][32][33] . To date, several excellent reviews on R 3+ doped upconversion luminescence have been published to summarize the progress in this field along with demonstration of advanced applications 34,35 .…”

Structural, magnetic and up-conversion properties of YF3: Yb/Ln (Ln = Er, Tm, Ho) solid solutions

“…The structure parameters of our samples were refined using the starting parameters from Ref. (Zalkin and Templeton, 1953). Some most important parameters from Rietveld analysis (lattice constants, cell volume, profile R-factors, crystallite size, microstrain) are summarised in Table 1.…”

“…In the last decades, lanthanide-doped up-conversion (UC) nanomaterials have attracted a lot of attention in the fields such as solid-state lasers, solar cells, temperature sensors, medical diagnostics, biomarkers, fiber-optic communication systems, ratiometric thermometry, etc. (Atabaev, 2019, Dramićanin, 2018, Escudero et al, 2017, Ho et al, 2019, Liu et al, 2011, Tiwari, 2018. These materials owe their popularity to their specific ability to convert near-infrared to high-energy photons (visible or ultraviolet), a process that results from the abundance of energy levels of 4f configurations (Atabaev, 2019, Auzel, 2003.…”

Recent Progress and Emerging Applications of Rare Earth Doped Phosphor Materials for Dye‐Sensitized and Perovskite Solar Cells: A Review

“…[158,159] In addition to the above mentioned applications, recently they found potential in area of vivo bioimaging, photodynamic therapy, photothermal therapy as well as deep 3D bioimaging due to wavelength tuning. [160,161] When the photo-responsive compounds and polymeric materials coupled with UCNPs they acts as a suitable candidates for drug delivery systems. With the utilization of UC/DC materials into solar photovoltaics, the maximum power conversion efficiency that can be achieved may be slightly higher than 30%.…”

“…when these rare earth doped luminescent materials are coupled with commercially available wide band gap semiconductors such as TiO 2 , it helps in fast degradation of inorganic and organic pollutants and water splitting under visible light irradiation . In addition to the above mentioned applications, recently they found potential in area of vivo bioimaging, photodynamic therapy, photothermal therapy as well as deep 3D bioimaging due to wavelength tuning . When the photo‐responsive compounds and polymeric materials coupled with UCNPs they acts as a suitable candidates for drug delivery systems.…”