Red photoluminescence in praseodymium-doped titanate perovskite films epitaxially grown by pulsed laser deposition

Abstract

Intense red photoluminescence ͑PL͒ under ultraviolet ͑UV͒ excitation was observed in epitaxially grown Pr-doped Ca 0.6 Sr 0.4 TiO 3 perovskite films. The films were grown on SrTiO 3 ͑100͒ substrates by pulsed laser deposition, and their epitaxial growth was confirmed by x-ray diffraction and reflected high-energy electron diffraction. The observed sharp PL peak centered at 610 nm was assigned to the transition of Pr 3+ ions from the 1 D 2 state to the 3 H 4 state. The PL intensity was markedly enhanced by postannealing treatments at 1000°C, above the film-growth temperature of 600 or 800°C. Because the excitation and absorption spectra are similar to each other, it was suggested that the UV energy absorbed by the host lattice was transferred to the Pr ions, resulting in the red luminescence.

Effects of doping and epitaxy on optical behavior of NaNbO3 films

“…We notice that in order to achieve such a bright luminescence in doped ferroelectric films, the required film thickness is usually 3-10 times larger. [24][25][26] The obtained spectrum of PL emission contains a strong narrow line at approximately 2 eV (wavelength 610 nm) in the Pr-doped film ( Figure 5(a)), closely resembling that at 620 nm in the Pr-doped NNO crystal. 9 Thus, also similar to the crystal, the red PL in the film can be ascribed to radiative transitions between the 1 D 2 excited state and the 3 H 4 ground state of Pr 3þ ions.…”

Photoluminescence in Low-Dimensional Oxide Ferroelectric Materials

“…We note that the red emission (612 nm) has been relatively weak for all Pr doping contents except Pr doping content of 0.01. This is very different from that of Pr 3+ doped SrTiO 3 and CaTiO 3 thin films in which the red emission is strongest whereas the blue-green emission is very weak [59,60]. This is because the photoluminescence properties of Pr 3+ are sensitive to host lattice symmetry.…”

“…It was found that the substrate properties such as optical absorbance and thermal conductivity affected the crystal growth and the PL emission of the thin films in the excimer laser assisted metal organic deposition process. Takashima, et al observed intense red photoluminescence under ultraviolet excitation in epitaxial Pr-doped Ca 0.6 Sr 0.4 TiO 3 perovskite thin films prepared on SrTiO 3 (100) substrates by pulsed laser deposition [74]. The observed sharp PL peak centered at 610 nm was assigned to the transition of Pr 3+ ions from the 1 D 2 state to the 3 H 4 state.…”

Structural disorder-dependent upconversion in Er3+/Yb3+-doped calcium titanate

“…In addition, rare earth iondoped calcium titanate (CaTiO 3 ) phosphors have been studied extensively due to their well-known chemical stability. In recent years, CaTiO 3 :Pr 3 þ has attracted much attention because high red-light emission appears only starting from the 1 D 2 (Pr 3 þ ) level in this material [6][7][8][9][10]. Several such materials show high-frequency upconversion luminescence on excitation with comparatively lower frequency excitation due to excited state absorption through metastable states.…”