Upconversion luminescence in Er3+ doped and Er3+/Yb3+ codoped zirconia and hafnia nanocrystals excited at 980 nm

Abstract

Frequency upconversion ͑UC͒ luminescence in nanocrystalline zirconia ͑ZrO 2 ͒ and hafnia ͑HfO 2 ͒ doped with Er 3+ and Yb 3+ was studied under continuous-wave excitation at 980 nm. Samples of ZrO 2 :Er 3+ , ZrO 2 :Er 3+ / Yb 3+ , and HfO 2 :Er 3+ / Yb 3+ were prepared by the sol-gel technique and characterized using x-ray diffraction and electron microscopy. A study of the infrared-to-green and infrared-to-red UC processes was performed including the analysis of the spectral and the temporal behavior. The mechanisms contributing to the UC luminescence were identified as excited state absorption and energy transfer among rare-earth ions.

Visible up-conversion and near-infrared luminescence of Er3+/Yb3+ co-doped SbPO4-GeO2 glasses

“…They also have visible emissions in the red and green regions caused by successive absorption of IR photons, leading the population to higher energy levels by upconversion. Both processes are enhanced when the glass host is co-doped with Yb 3þ ions, due to their larger absorption cross section than Er 3þ ions at 980 nm, and processes of excited state absorption as well as energy transfer from Yb 3þ to Er 3þ ions [3,4].…”

Tailoring the Structure and Luminescence of Nanostructured Er3+ and Er3+/Yb3+‐Activated Hafnia‐Based Systems

“…Recently, some of us have published studies on the frequency upconversion (UC) luminescence of Er 3+ /Yb 3+ ‐doped nanocrystalline HfO 2 under continuous wave excitation at 980 nm. Infrared‐to‐green and infrared‐to‐red UC processes were investigated and the mechanisms contributing to the UC luminescence were identified as excited state absorption and energy transfer among rare‐earth ions . Lately, optical properties were reported for Eu 3+ and Tb 3+ stabilized cubic HfO 2 nanoparticles, which were prepared by a nonaqueous sol–gel method starting from metal alkoxide precursor …”

Recent advances in lanthanide spectroscopy in Brazil

“…Other investigations on the luminescence properties of lanthanide-based systems with NPs, nanorods or systems assembled using sol-gel techniques have been reported in the literature [17,22,27,33,34,38,40,43,45,49,50,60,61,67,73,78,82,88,93,107,[127][128][129]133,136,140,142,143,149,163,[169][170][171]176,178,201,211,212,214,[235][236][237][238][239][240][241][242][243][244][245]…”