Polarization‐Induced Photoluminescence Quenching in (Ba_0.7Ca_0.3TiO₃)–(BaZr_0.2Ti_0.8O₃):Pr Ceramics

Abstract

Pr 3+ -doped (Ba 0.85 Ca 0.15 )(Zr 0.1 Ti 0.9 )TiO 3 ceramics were prepared by a solid-state reaction method. The effects of doping concentration, sintering temperature, and ferroelectric remanent polarization on photoluminescence (PL) properties of samples were systematically investigated. The PL spectra of samples exhibit strong green and red emissions with a broad blue excitation band ranging from 430 to 500 nm, in a good agreement with all commercial blue LEDs emission wavelength. Except for the concentration and temperature PL quenching, the polarization-induced PL quenching was obviously observed, and the degree of PL quenching changes with Pr 3+ concentrations, the origin of the change is well interpreted by field-induced structural phase transitions between rhombohedral (R3m) and tetragonal (P4mm) for BCZT: xPr ceramics near the morphotropic phase boundary.

In-situ Electric Field-Induced Modulation of Photoluminescence in Pr-doped Ba0.85Ca0.15Ti0.90Zr0.10O3 Lead-Free Ceramics

“…Finally, the diffraction peak becomes relatively narrow with an evident (200) R peak under an electric field of 2 kV/mm, revealing a transformation from a mainly tetragonal phase into a mainly rhombohedral phase. This unique ferroelectric phase evolution corresponds to the symmetry-raising characteristic, and agrees well with previous literature21 and the established ferroelectric phase diagram26. Although the (002) peak cited by the orthorhombic phase may exist in the ceramic, we regard it as an instable intermediate phase induced by E-field dependent phase evolution4142.…”

“…Probably due to the slight differences in compositions which could influence the cross-relaxation process of Pr 3+  43, the strongest red emission occurs at 650 nm (Fig. 4), instead of 600 nm reported for the (Ba 0.85 Ca 0.15 ) 1-x Pr x (Zr 0.1 Ti 0.9 )O 3 ceramics21. Owing to its strong intensity and f-f transition characteristics, the emission at 650 nm has been selected for studying the dynamic PL emissions under external electric field.…”

“…The uneven components enhance the electronic coupling between 4f energy levels and higher 4f5d configuration and subsequently increase f–f transition probabilities of the dopant ions19. The common approaches for ferroelectric hosts to rationally tune structural symmetry are based on those coupling physical factors that can respond well to external electric field such as biaxial strain1420, polarization2212223, or phase transition2425.…”

Varistor, Dielectric, and Luminescent Properties of Pr6O11‐doped TiO2 Multifunctional Ceramics

“…The broad excitation band centered at around 390 nm could be attributed to the Ti 4+ (3 d )→Pr 3+ (4 f ) intervalence charge transition (IVCT model) . Several weak peaks between 440 and 560 nm are due to the typical f – f transition of Pr 3+ , namely, the peaks around 446, 466, 479, 490, and 553 nm corresponding to the 3 H 4 → 3 P 2 , 3 H 4 → 1 I 6 , 3 H 4 → 3 P 1 , 3 H 4 → 3 P 0 , and 3 H 5 → 3 P 0 …”

Physical Manipulation of Lanthanide‐Activated Photoluminescence

“…Moreover, electric field-induced polarization could also cause an obvious reduction of luminescence intensity in Pr 3+ -doped (Ba 0.85 Ca 0.15 )(Zr 0.1 Ti 0.9 )TiO 3 ceramics, which may be due to electric field-induced crystal symmetry increase as the structure transforms from tetragonal to rhombohedral phases. [97] Specially, Mundoor et al [98] acquired electrically tunable upconversion emission in an elaborated composite material of upconversion nanorods and liquid crystal, and attributed it to the rotation of nanorods and the change of crystal field symmetry in Reproduced with permission. [99] Copyright 2018, American Chemical Society.…”