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Luminescent piezoelectric materials promise a stratagem for controlling the optical process by electric field, which would benefit for future optoelectronic devices. Here, Er3+ doped (Ba 0.85 Ca 0.15) (Zr 0.1 Ti 0.9)O 3 (BCZT: Er3+) piezoelectric ceramics are prepared to demonstrate the proof of concept. In addition to excellent intrinsic piezoelectricity and ferroelectricity, BCZT: Er3+ ceramics exhibit simultaneously strong green upconversion emissions under excitation of 980 nm. Remarkable photoluminescence (PL) quenching phenomenon as well as significant changes on relative intensities of stark lines are observed under external poling electric field. Furthermore, field dependent piezoelectric constant d 33 and photoluminescence quenching ratio show similar variation trend and finally saturate for E > 3.5 kV/mm, which provides a noncontact strategy to monitor the piezoelectric constant d 33. The PL quenching triggered by electric field in BCZT: Er3+ ceramics is ascribed to the decreased asymmetry originating from field-induced structural transformation from a significant fraction of the tetragonal phase to rhombohedral phase. Our work would be helpful for expanding the scope of luminescent piezoelectric materials and promising future optoelectronic and optical devices with cross-coupled physical properties. • Ferroelectricity and upconversion emissions coexist in BCZT: Er3+. • Electric field can modulate photoluminescence and relative intensity of stark lines. • A noncontact strategy to monitor the piezoelectric constant is proposed. • The mechanism of electric field-photoluminescence coupling is analyzed. [ABSTRACT FROM AUTHOR]

Abstract A series of orange-red emitting Sm3+ activated Ba 0.85 Ca 0.15 Ti 0.90 Zr 0.10 O 3 (BCZT: x Sm3+, x = 0.001–0.007) are synthesized by a conventional solid-state reaction method. The Sm3+ ions composition dependent photoluminescence properties are systematically investigated. Under the excitation of a 407 nm near-ultraviolet light, the ceramics exhibit strong characteristic emission of Sm3+ ions with dominant orange-red emission peak at around 595 nm, which is ascribed to the transition of 4G 5/2 → 6H 7/2. The BCZT: 0.004Sm3+ ceramic displays the optimal emission among these Sm3+-doped BCZT solid solutions. Moreover, the photoluminescence intensity exhibits extremely sensitive to temperature, suggesting that BCZT: 0.004Sm3+ could be applicable for temperature sensing. A maximum relative sensitivity of 1.89% K−1 at 453 K is obtained. Furthermore, the existence of ferroelectricity in the BCZT host combined with Sm3+ activated photoluminescence properties could be useful for developing optical-electro multifunctional materials and devices. [ABSTRACT FROM AUTHOR]

Luminescent temperature sensors based on photoluminescent materials have received considerable attention for their advantages of quick and noninvasive measurement. In this paper, a series of Tb3+, Eu3+ single-doped and co-doped Ca 2 Al 2 SiO 7 (CAS) phosphors were synthesized by sol-gel method. The phase purity, surface morphology, energy transfer, luminescence characteristics and temperature sensing properties of Tb3+, Eu3+ doped CAS phosphors have been studied carefully. Due to the energy transfer of Tb3+→Eu3+, CAS: Tb3+, Eu3+ phosphors demonstrate tunable luminescence under 238 nm excitation, in which the luminescence color gradually changes from purple-red to cool white, and then to warm white by continuously increasing the concentration of Tb3+ ions. The elongation of the fluorescence lifetime of Eu3+ with increasing Tb3+ ions content further confirms the energy transfer of Tb3+→Eu3+. The thermal behavior of CAS: Tb3+, Eu3+ phosphors shows enhanced luminescence intensity for 404 nm emission while suppressed luminescence intensity for 616 nm emissions with raising temperature, implying its potential in optical temperature sensing. Therefore, the temperature sensing performance is evaluated by using the fluorescence intensity ratio (I 404 nm /I 616 nm) in CAS: Tb3+, Eu3+ phosphors, showing a maximum relative sensitivity of 1.17%K−1 at 443 K. These results indicate that CAS: Tb3+, Eu3+ phosphors are promising candidates for tunable luminescence and non-contact temperature sensing. [ABSTRACT FROM AUTHOR]

A series of Sr 3 La 2 (PO 4) 2 (SiO 4)O: Eu2+ phosphors were synthesized by conventional high-temperature solid-state reaction. The phase formation was confirmed by XRD analysis. The photoluminescence properties of Sr 3 La 2 (PO 4) 2 (SiO 4)O: Eu2+ phosphors were investigated systematically. The phosphors exhibit absorption in the ultraviolet–visible spectral region of 280–420 ​nm and show an intense asymmetric broadband blue emission peaking at 454 ​nm under the excitation at 365 ​nm. The concentration quenching mechanism, decay property, and thermal stability have been discussed in detail. The investigation results indicate that Sr 3 La 2 (PO 4) 2 (SiO 4)O: Eu2+ will have applications as the blue component in tricolor near-ultraviolet pumped white light-emitting diodes. The Sr 3 La 2 (PO 4) 2 (SiO 4)O: Eu2+ phosphor was reported, which shows the potential application as a blue component in tricolor n-UV pumped wLEDs. Image 1 [ABSTRACT FROM AUTHOR]