Structure Evolution and Up‐Conversion Studies of ZnX2O4:Er3+/Yb3+ (X = Al3+, Ga3+, In3+) Nanoparticles. Issue 6 (15th January 2014)

• Record Type: Journal Article
• Authors: Wiglusz, R. J.; Watras, A.; Malecka, M.; Deren, P. J.; Pazik, R.
• Is Part Of: European journal of inorganic chemistry. Issue 6(2014)
• Page Start: 1090
• Page End: 1101
• Publication Date: 2014-01-15
• Subjects: Nanoparticles -- Spinel phases -- Rare earths -- Luminescence -- Phosphors -- Modified Pechini technique; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201301351
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: A series of ZnX2 O4 :Er 3+ /Yb 3+ (X = Al 3+, Ga 3+, In 3+ ) nanoparticles were obtained by using a modified Pechini technique. The crystal structure, morphology, and chemical composition of the engineered compounds were characterized in detail by means of X‐ray diffraction, Micro‐Raman spectroscopy, transmission electron microscopy (TEM) and selected area electron diffraction, and energy‐dispersive X‐ray spectroscopy. Particle sizes were estimated by using theoretical calculations (Scherrer and Rietveld methods) as well as experimental techniques [TEM and dynamic light scattering (DLS)] and were, furthermore, cross‐compared. The calculated average grain size, for dry powders, is in the range 20–45 nm. The hydrodynamic size was measured by using the DLS technique on nonmodified, surfactant‐free particles of the whole ZnX2 O4 series. The up‐conversion properties of the particles were discussed in detail. The low value of the green‐to‐red ratio points to a significant contribution of non‐radiative pathways, such as multiphonon relaxation or cross relaxation processes, to the depopulation of the green band, which feeds and favors the red emission of Er 3+ in the up‐conversion process. Abstract : A series of phase‐pure ZnX2 O4 nanoparticles co‐doped with Er 3+ /Yb 3+ with grain sizes in the range 20–45 nm have been synthesized. Er 3+ and Yb 3+ ions exchange both metal sites in ZnAl2 O4 and ZnGa2 O4 . In the ZnO· In2 O3 composite, only In 3+ ions are replaced by the dopants. The composite material based on the ZnO· In2 O3 solid solution showed the best up‐conversion efficiency.