The Art of Nanoparticle Design: Unconventional Morphologies for Advancing Luminescent Technologies

The advanced design of rare-earth-doped (RE-doped) fluoride nanoparticles has expanded their applications ranging from anticounterfeiting luminescence and contactless temperature measurement to photodynamic therapy. Several recent studies have focused on developing rare morphologies of RE-doped nanoparticles. Distinct physical morphologies of RE-doped fluoride materials set them apart from contemporary nanoparticles. Every unusual structure holds the potential to dramatically improve the physical performance of nanoparticles, resulting in a remarkable revolution and a wide range of applications. This comprehensive review serves as a guide offering insights into various uniquely structured nanoparticles, including hollow, dumbbell-shaped, and peasecod-like forms. It aims to cater to both novices and experts interested in exploring the morphological transformations of nanoparticles. Discovering new energy transfer pathways and enhancing the optical application performance have been long-term challenges for which new solutions can be found in old papers. In the future, nanoparticle morphology design is expected to involve more refined microphysical methods and chemically-induced syntheses. Targeted modification of nanoparticle morphology and the aggregation of nanoparticles of various shapes can provide the advantages of different structures and enhance the universality of nanoparticles.

White-light emission in Yb3+/Er3+/Tm3+- and Yb3+/Er3+/Tm3+/Ho3+-dopedα-NiMoO4nanoparticles

Yb³⁺/Er³⁺/Tm³⁺- and Yb³⁺/Er³⁺/Tm³⁺/Ho³⁺-dopedα-NiMoO₄nanoparticles were synthesized using a microwave hydrothermal method and studied for white-light emission under 980 nm laser diode excitation. White upconversion (UC) light was successfully obtained with the appropriate control of blue, green, and red emissions by successfully tuning the Er³⁺and Ho³⁺concentrations in Yb³⁺/Er³⁺/Tm³⁺- and Yb³⁺/Er³⁺/Tm³⁺/Ho³⁺-dopedα-NiMoO₄, respectively. In addition, the white color emission was shown by the CIE chromaticity coordinates of samples. The energy transfer mechanisms are explained in detail based on the emission spectra and pump power density-dependent UC luminescence intensity in rare earth (Yb³⁺/Er³⁺/Tm³⁺and Yb³⁺/Er³⁺/Tm³⁺/Ho³⁺)-dopedα-NiMoO₄nanoparticles. The results indicate that Yb³⁺/Er³⁺/Tm³⁺- and Yb³⁺/Er³⁺/Tm³⁺/Ho³⁺-dopedα-NiMoO₄nanoparticles can be good candidates for white-light devices.