Effect of annealing and Nd concentration on the photoluminescence of Nd3+ ions coupled with silicon nanoparticles

Abstract

The Nd-nanocluster coupling strength and its effect in excitation/de-excitation of Nd 3+ luminescence in Nddoped silicon-rich silicon oxide Appl. Phys. Lett. 83, 2778Lett. 83, (2003 We report on the microstructure and photoluminescence ͑PL͒ properties of Nd-doped SiO 2 thin films containing silicon nanoparticles ͑Si-np͒ as a function of the annealing temperature and the Nd concentration. The thin films, which were grown on Si substrates by reactive magnetron co-sputtering, contain the same Si excess. Fourier transform infrared ͑FTIR͒ spectra show that a phase separation occurs during the annealing due to the agglomeration of the Si excess resulting in the formation of Si-np. Besides, after annealing, the films exhibit PL from excitonic states confined in Si-np. We showed that the intensity of the PL of Nd 3+ ions that occurs at ϳ0.92, 1.06, and 1.4 m is maximal at low Nd concentration and while well-passivated Si-np are formed. FTIR and x-ray measurements showed that the increase in the Nd incorporation has detrimental effects on the PL of Nd 3+ because of the formation of Nd 2 O 3 nanocrystals and inherent disorder in the SiO 2 host matrix. PL excitation measurements demonstrate that the PL of Nd 3+ ions is nonresonant and follows the excitation of Si-np giving new evidence of the energy transfer from Si-np toward the rare earth ions.

Microstructure and optical properties of Pr3+-doped hafnium silicate films

“…Taking into account the formation of Si-ncs in Pr-doped HfSiO x samples annealed at 1,100°C for 1 h, one can expect the appearance of a PL emission due to exciton recombination inside Si-ncs, which is usually observed in the 700- to 950-nm spectral range [17,18]. However, our study of these samples did not reveal the Si-nc PL emission.…”

“…At the initial stage, the annealing process is supposed to decrease the non-radiative recombination rates [24]. Thereafter, the quenching of the Pr 3+ emission that occurred for T A > 1,000°C can be due to the formation of the Pr 3+ silicate or Pr oxide clusters (Figure 2) similar to the case observed in [17,18]. Moreover, it is interesting to note that the position of peak (Pr 3+ : 3 P 0 → 3 H 4 ) redshifts from 487 nm ( T A ≤ 1,000°C) to 492 nm ( T A = 1,100°C) as shown in Figure 4c.…”

Recent advances in energy transfer in bulk and nanoscale luminescent materials: from spectroscopy to applications

“…Namely, the SPR band of the plasmonic materials has to be in resonance with the absorption of the luminescent centers. [220][221][222] This on the other hand implies that the plasmon enhancement of emission is a near field effect and it occurs only in carefully designed nanosystems where the ''hot spot'' of the electric field and the emitters are positioned in the correct distance and geometry with respect to each other. The localized SPR of Ag or Au nanostructures which are located in the visible region have been used to enhance the PL of diverse materials, from colloidal QDs to RE doped nanoparticles and organic or bio-organic molecules.…”

Influence of Nd dopant amount on microstructure and photoluminescence of TiO2:Nd thin films

“…1090 nm, which is the most interesting from the application point of view in e.g. lasers [2][3][4]. Intensity, position and complicated structure of all observed emission lines for films doped with Nd in the range from 0.6 to 2.0 at.% are related not only to the electron transitions between Nd 3+ particular energy levels but also are strongly influenced by different surroundings of the Nd ions due to the different microstructure of prepared thin films.…”