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Tunable luminescence and efficient energy transfer investigation of a borosilicate phosphor KBSi 2 O 6 : Bi3+, Eu3+. [Display omitted] • Novel borosilicate phosphor KBSi 2 O 6 : Bi3+, Eu3+ are successfully synthesized. • Phase purity and tunable luminescence of KBSi 2 O 6 : Bi3+, Eu3+ are studied. • Effective energy transfer between Bi3+ and Eu3+ is demonstrated. • Hypersensitive thermal quenching is investigated with high S a and S r. Energy transfer between Bi3+ and Eu3+ has undergone substantial research but Bi3+ and Eu3+ co-doped luminescent materials with high energy transfer efficiency for temperature sensing are rarely investigated until now. Herein, Eu3+ and Bi3+ co-doped KBSi 2 O 6 phosphors were successfully synthesized by solid-state reaction method. The phase purity structure as well as the element distribution were carefully investigated through X-ray diffraction structural refinement and energy dispersive spectrometer analysis. The characteristic luminescence property and luminescence kinetics of KBSi 2 O 6 : Bi3+, Eu3+ were investigated. By the large spectra overlap between the emission spectrum of Bi3+ and excitation spectrum of Eu3+, the energy transfer from Bi3+ to Eu3+ can be inferred. The corresponding decrease of the emission intensity and decay time of Bi3+ in KBSi 2 O 6 : Bi3+, Eu3+ provided direct evidence for the effective energy transfer from Bi3+ to Eu3+. The interaction and energy transfer mechanism between Bi3+ and Eu3+ ions were also studied. By increasing the Eu3+ concentration in KBSi 2 O 6 : Bi3+, Eu3+, the color-tunable emission from blue to red can be realized. KBSi 2 O 6 : Bi3+, Eu3+ shows hypersensitive thermal quenching behavior and the maximum absolute sensitivity (S a) and relative sensitivity (S r) are determined to be 1.87 %K−1 and 2.895 %K−1, respectively. All of the above results imply that KBSi 2 O 6 : Bi3+, Eu3+ phosphor can be a color-tunable phosphor for optical temperature sensing. [ABSTRACT FROM AUTHOR]

Compounds with Cs 3 CoCl 5 structure usually exhibit a large Debay temperature with a large band gap, which has been considered as new host materials for WLED application. Oxide materials of the Cs 3 CoCl 5 structure have great luminescence characteristics, thus it is more worthwhile to research Cl-based materials with higher electronegativity. Here, an Mn2+ activated Cs 3 ZnCl 5 narrow band green emitting phosphor was developed and investigated in detail. Ternary alkaline chloride Cs 3 ZnCl 5 was successfully prepared by a coprecipitation method. XRD refinement, SEM and XPS have proved the successful preparation of Cs 3 ZnCl 5 : 6%Mn2+ with a single phase. The electronic structure investigation clearly states that Cs 3 ZnCl 5 has a large band gap with Eg∼4.467 eV. The Cs 3 ZnCl 5 : 6%Mn2+ phosphor can also generate green light with a peak wavelength of 525 nm and a fullwidth at half-maximum (FWHM) of 47 nm when excited by blue light at 451 nm. The luminescent property, as well as the concentration-dependent emission decay behavior of Cs 3 ZnCl 5 : 6%Mn2+ at room temperature, were studied. Over the temperature range of 30–120 °C, the thermal quenching performance of Cs 3 ZnCl 5 : 6%Mn2+ was investigated, and the related mechanism was discussed through thermoluminescence analysis. Electron traps transmit energy to the Mn2+ luminescence center after 120 °C, which will increase the emission intensity. Finally, a blue light-pumped white LED was constructed using this phosphor in combination with commercially available red phosphors. The findings above suggested that Cs 3 ZnCl 5 : 6%Mn2+ could be served as a potential green-emitting phosphor for white light-emitting diodes. • The Cs 3 ZnCl 5 : Mn2+ phosphors are successful prepared. • The abnormal thermal quenching have been discussed in detail. • The Cs 3 ZnCl 5 : Mn2+ phosphors have a green emitting at 525 nm. • The Cs 3 ZnCl 5 : Mn2+ phosphors can be used in WLEDs. [ABSTRACT FROM AUTHOR]

An efficient and ultra‐broadband red phosphor CsMg2P3O10: Mn2+ (CMPO: Mn2+) is first synthesized toward indoor plant growth LEDs. The phase purity, element composition, crystal, and local electronic structure are explored to discuss the structure and photoluminescence properties. Structure refinement and series X‐ray diffractometer (XRD) results show that CMPO: Mn2+ is well crystallized in an orthogonal crystal system. The diffuse reflection and excitation spectra show that CMPO: Mn2+ has strong absorption around near ultraviolet region, assigned to the [6A1 → 4E(4D), 4T2(4D), [4A1(4G), 4E(4G)], and 4T1(4G)] transitions of Mn2+, respectively. Upon 415 nm excitation, an efficient red emission centered at 647 nm with ultra‐broad full width at half‐maximum (FWHM ∼ 100 nm) and high quantum efficiency (IQE ∼ 44.3 %) is observed, and because of the ultra‐broad FWHM, the red emission is well accordant with the absorption spectra band of phytochrome PR and PFR. The optimal doping contents, lifetime as well as interaction mechanism of CMPO: Mn2+ are discussed in detail. Finally, the excellent thermal stability (84.5% @ 140°C) and related thermal quenching mechanism of CMPO: Mn2+ are discussed. The above results indicate that CMPO: Mn2+ phosphors have great potential for application in plant growth LEDs. [ABSTRACT FROM AUTHOR]