Nanophosphors

Novel single, double and triple doped ZnA O M and ZnGa204 M (where M = Dy3+, Tb3+, Eu3+ and Mn2+) nanophosphors were also synthesized through a simple sonochemical process [42]. 

Dutta DP, Ghildiyal R, Tyagi AK (2009) Luminescent properties of doped zinc aluminate and zinc gallate white light emitting nanophosphors prepared via sonochemical method. J Phys Chem C 113(39) 16954-16961... 

Kamimura M, Miyamoto D, Saito Y, Soga K, Nagasaki Y (2008) Design of polyethylene glycol)/streptavidin co-immobilized upconversion nanophosphors and their application to fluorescence biolabeling. Langmuir 24 8864-8870... 

Kamimura M, Kanayama N, Tokuzen K, Soga K, Nagasaki Y (2011) Near-infrared (1550 nm) In vivo bioimaging based on rare-earth doped ceramic nanophosphors modified with PEG-b-poly (4-vinylbenzyl phosphonate). Nanoscale. doi 10.1039/ClNR10466G... 

The advances in nanotechnology and synthesis methods have enabled nanomaterials to be produced in various shapes and structures. Coating of a luminescent layer activated by lanthanide ions on nanoparticles such as SiC>2 or AI2O3 is one of such approaches to develop new nanophosphors. In section 6, we review recent work on interesting spectroscopic features and luminescence dynamics of lanthanide ions in other novel low-dimensional nanostructures including core-shell, one-dimensional (ID) nanowires and nanotubes, two-dimensional (2D) nanofilms, hollow nanospheres, 2D nanosheet and nanodisk which have also attracted extensive attention. 

Upconversion lanthanide-containing nanophosphors, which emit higher-energy photons when excited by lower-energy photons have stirred increasing research interest in recent years. The predominant mechanisms of upconversion in nanophosphors are excited-state absorption (ESA), energy-transfer upconversion (ETU) and photon avalanche (PA) (Prasad, 2004 Auzel, 2005). In the ESA process, two photons are sequentially absorbed by the same ion,... 

Haase and co-workers have extensively studied the synthesis of high-quantum-yield nanophosphors such as Eu-, Tb- or Er-doped lanthanide phosphates (Riwotzki et al., 2000, 2001 Lehmann et al., 2004 Kompe et al., 2003 Lehmann et al., 2003). For example, the photoluminescence (PL) quantum yield of the CePO Tb core nanocrystals (4-6 nm) diluted... 

Due to size confinement on electronic interactions and density of phonon states, nano-structured materials exhibit distinct optical, magnetic and thermal properties in comparison with their bulk counterparts. Currently, there is growing interest for understanding how the confinement and other nanoscale mechanisms of electronic interactions in nanophosphors affect luminescence efficiency and photodynamics for such applications as three-dimensional displays, high-performance fight emitting devices, and highly sensitive bioassays. 

Luminescence of other doped rare earth borate nanophosphors... 

Li et al. developed a simple and versatile strategy for converting hydrophobic rare earth nanophosphors into water-soluble and carboxylic acid-functionalized analogues. The surface oleic acid ligands could be directly oxidized by the Lemieux-von Rudloff reagent, and the modified NCs kept the excellent luminescence and were further used as DNA labels (Figure 77) (Chen et al., 2008c). 

Rare Earth Nanophosphors with Upconversion Luminescence... 

However, such two-step conversion strategies for upconversion nanophosphors have some intrinsic limitations, such as complicated preparation and post-treatment procedures. Therefore, one-pot synthesis of water-soluble and surface-functionalized UCNPs has been attracting more attention. The groups working with Zhang [127] and Liu [128] employed... 

Rare Earth Upconversion Luminescence Nanophosphors as Bioimaging Nanoprobes... 

Figure 13.42 (a) UCL intensity along the line shown in UCL image (inset) of UCNPs-FA-treated HeLa cell and (b) the normalized UCL intensity as a function of illumination time [129]. (Reproduced from Biomaterials, 30, L.Q. Xiong et ah, Synthesis, characterization, and in vivo targeted imaging of amine-functionalized rare-earth up-converting nanophosphors, 5592-5600, 2009, with permission from Elsevier.)... 

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