Preparation and luminescence of nano-sized In 2 O 3 and rare-earth co-doped SiO 2 thin films

Applied Physics Letters

et al. 2008

Self Cite

A significant enhancement of photoluminescence from Eu3+ embedded in SiO2 matrix is observed by codoping with wide band-gap In2O3 nanoparticles. The enhanced photoluminescence characteristics are strongly influenced by the postannealing temperature and the In3+ concentration. Synchronous scanning photoluminescence technique was used to understand the excitation and luminescence behavior in codoped silica films. Based on the experimental results, we argue that the enhancement of photoluminescence is associated with the effective energy transfer process from In2O3 nanoparticles to the charge transfer band of O2+–Eu3+ instead of the direct transfer to the rare-earth energy levels.

Section: B͒supporting

confidence: 90%

Section: B͒mentioning

confidence: 99%

See 1 more Smart Citation

Energy transfer and enhanced luminescence in metal oxide nanoparticle and rare earth codoped silica

Wan

Applied Physics Letters

et al. 2008

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“…Co-doping of semiconductor nanocrystals with europium (Eu) ions in silica thin films has been found to enhance significantly the characteristic emission at 614 nm [5−8] . The detailed excitation and luminescence process are still not fully understood, although the energy transfer mechanism has been proposed to explain the enhanced luminescence [9] . The co-doped nanocrystals are believed to act as sensitizers (donor) in a host matrix to enhance the luminescence from Eu 3+ ions (activator) by non-radiative energy transfer process.…”

Section: Ermentioning

confidence: 99%

Photoluminescence from Er3+ ion and SnO2 nanocrystal co-doped silica thin films

Zhang

et al. 2012

中国光学快报

Er3+ ions embedded in silica thin films co-doped by SnO2 nanocrystals are fabricated by sol-gel and spin coating methods. Uniformly distributed 4-nm SnO2 nanocrystals are fabricated, and the nanocrystals showed tetragonal rutile crystalline structures confirmed by transmission electron microscope and X-ray diffraction measurements. A strong characteristic emission located at 1.54 µm from the Er 3+ ions is identified, and the influences of Sn doping concentrations on photoluminescence properties are systematically evaluated. The emission at 1.54 µm from Er 3+ ions is enhanced by more than three orders of magnitude, which can be attributed to the effective energy transfer from the defect states of SnO2 nanocrystals to nearby Er 3+ ions, as revealed by the selective excitation experiments. OCIS codes: 160. 4236, 160.5690, 160.2160, 260.3800. doi: 10.3788/COL201210.091603.There has been a growing interest in strong luminescence from rare-earth (RE) ions in the silica matrix because of their practical applications in high-brightness displays and optical communications [1−4] . However, the optical cross-sections of RE ions are usually rather small, resulting in low emission efficiency. This problem may be remedied by introducing semiconductor nanocrystals into the RE ion-doped silica thin films. Co-doping of semiconductor nanocrystals with europium (Eu) ions in silica thin films has been found to enhance significantly the characteristic emission at 614 nm [5−8] . The detailed excitation and luminescence process are still not fully understood, although the energy transfer mechanism has been proposed to explain the enhanced luminescence [9] . The co-doped nanocrystals are believed to act as sensitizers (donor) in a host matrix to enhance the luminescence from Eu 3+ ions (activator) by non-radiative energy transfer process.The characteristic emission at 1.54 µm from erbium (Er) ions is very important, especially in Si-based photonics [10] . The energy transfer from semiconductor nanocrystals to Er 3+ ions, by co-doping the semiconductor nanocrystals, can efficiently compensate the small cross-section of transitions of Er 3+ ions, typically in the order of 10 −21 cm −2 [11,12] . In this letter, we use sol-gel and spin coating technique to prepare silica thin film co-doped by SnO 2 nanocrystals and Er 3+ ions. SnO 2 nanocrystals can act as sensitizers in silica films, and their wide band gap (approximately 3.6 eV) can prevent the back energy transfer process efficiently [13−15] . Moreover, SnO 2 nanocrystals can be easily prepared in a controllable manner during sol-gel fabrication process, and their thermal stability is better than those of In 2 O 3 [8,16] and ZnO [17] nanocrystals. Results from transmission electron microscopy and X-ray diffraction show that the prepared SnO 2 nanocrystals have the average size of 4 nm and exhibit tetragonal rutile structures. The emission of 1.54 µm from Er 3+ ions can be observed at room temperature from Er 3+ ion and SnO 2 nanocrystal co-doped silica thin films. The influence of Sn...

“…19 The formation of metal oxide NCs in silica films and the elimination a National Laboratory of Solid State Microstructures, School of Electronic Science of -OH groups as the most common non-radiative recombination centres are readily influenced by the annealing temperature. 20 According to the thermo-gravimetric and differential scanning calorimetry (TG/DSC) tests, 21 the thermal process above 400 1C is an essential prerequisite for the formation of silica films because of the pyrolysis of the residual carbide in TEOS. Herein we report that the near-infrared emission intensity from Er 3+ ions/SnO 2 NCs co-doped samples is enhanced by more than two orders of magnitude via size control to boost the sensitization efficiency with increasing annealing temperature up to 1000 1C.…”

Section: Introductionmentioning

confidence: 99%

Improved sensitization efficiency in Er³⁺ ions and SnO₂ nanocrystals co-doped silica thin films

Zhang

Phys. Chem. Chem. Phys.

et al. 2015

Self Cite

Er(3+) ions and SnO2 nanocrystals co-doped silica thin films are prepared by an improved sol-gel spin-coating method. With increase in annealing temperature, the related 1.54 μm characteristic emission intensity from Er(3+) ions is obviously enhanced by more than two orders of magnitude via SnO2 nanocrystals size control to boost the sensitization efficiency. Quantitative studies of steady-state spectroscopic data and fluorescence decay curves demonstrate that the related sensitization efficiency via size-tunable nanocrystals is increased from 0.14% to 1.3%. This improved sensitization efficiency is achieved by doping some of the Er(3+) ions into the SnO2 inner sites at a high annealing temperature, as revealed by high-resolution TEM, X-ray diffraction patterns and elemental mapping technique. Different sensitization mechanisms are also discussed separately according to the selective photoluminescence excitation measurements. All these results have not only explained the greatly improved sensitization efficiency resulting from SnO2 nanocrystals but also indicated that the development of Er(3+) ions and SnO2 nanocrystals co-doped silica thin films could result in promising high-performance near-infrared luminous materials using broadband UV pumping.