Crystalline SnO₂ Nanoparticles Size Probed by Eu³⁺ Luminescence

Abstract

Size-controlled europium(III)-doped SnO 2 nanoparticles dispersed inside of porous Vycor glass (PVG) were synthesized using the impregnation and decomposition cycle (IDC) method. XRD, DRS, and TEM analyses proved that the observed cumulative mass gain after each IDC is associated to a controlled growing of the SnO 2 nanoparticles. Europium(III) emission spectra were acquired for all samples and clear differences on the relative intensity of the 5 D 0 f 7 F 2 / 5 D 0 f 7 F 1 transitions were observed for different SnO 2 nanoparticle sizes. The changes in the europium(III) emission spectra could be correlated with the increase of nanoparticle sizes. The smaller superficial nanoparticle area decreases the amount of europium(III) at the surface, where it can be located in different environments over distorted symmetry sites, compared to the crystal lattice sites, where the ions probably are located, when the particles become bigger with no changes in their crystallinity degree. The linear plot between the asymmetric intensity ratio of the 5 D 0 f 7 F 2 / 5 D 0 f 7 F 1 transitions and the particles area/volume ratio calculated from the XRD Scherrer data and particle size frequency counts (∼1/d) confirmed this behavior.

Nanoscale insights into doping behavior, particle size and surface effects in trivalent metal doped SnO2

“…To date, literature generally describes a complex Eu related emission in SnO 2 with both broad and narrow spectral features that changes strongly varies with Eu concentration, synthesis approaches, thermal treatment and excitation conditions used in luminescence measurements 28–32, 34, 63 . Here, we have extensively analyzed several tens of emission spectra of Eu-SnO 2 calcined in air at 700 and 1000 °C at 80 and 300 K using various excitation wavelengths spanning the UV to Vis range and gate/time delays after the laser pulse (Figure S6).…”

“…Comparison with an additional Eu-SnO 2 sample grown by a simple sol-gel method give identical emission shapes to those obtained for samples grown by rapid hydrothermal approach. Besides, according to our extensive literature survey on the luminescence of Eu-SnO 2 published over the last two decades, part of the emission related to centers II – IV can be observed as strongly non-separated, overlapped emission, though discernable in Eu-SnO 2 grown by sol-gel 30, 31, 34, 72 glass-ceramic waveguides 32 , hydrolysis 73 , impregnation and decomposition cycle method 63 , etc. Taken together, the emission shapes and narrowness (few cm −1 , comparable to that of C 2h center) suggest that centers II–IV are intrinsic to SnO 2 , resulting from the association of substitutional Eu with nearby bulk defects, most probably oxygen vacancy.…”

On the electrical properties of distinct Eu3+ emission centers in the heterojunction GaAs/SnO2

“…A linear relationship between asymmetry and particle area-volume ratio was observed, and correlated with the number of distorted Eu 3+ surface sites. [4] Concerning the electrical properties, incorporation of Eu 3+ in the SnO 2 layer leads to high charge compensation since the rare-earth doping acts as acceptors in the n-type A C C E P T E D M A N U S C R I P T…”

Lanthanide-doped semiconductor nanocrystals: electronic structures and optical properties

“…Recently, Complex precursor method. [47] ZnO Eu, Er Hydrothermal [22,48,49] Er Atomic layer deposition [50] Dy, Tb, Er Isocrystalline core-shell (ICS) protocol [51] Eu, Pr Hydrothermal [52−54] Eu Electrochemical deposition [55] Er Ligand-capped/ligand-exchanging [56] Pr, Sm, Tb, Ho, Tm, Eu Sol-gel [17,57−59] Dy, Yb, Pr, Sm, Er Sol-gel [60−63] Er, Eu Chemical combustion [64,65] SnO 2 Nd Deposition [66] Eu Co-decomposition [38] Eu Impregnation and decomposition cycle [67] Eu Thermal evaporation [68] Er, Eu, Solvothermal [69−71] Tm Implantation [72] Eu Microwave synthesis [21] Eu Solid state chemical reaction [73] Er, Yb, Eu …”