Mn-doped YMgTiO phosphors are synthesized by the traditional solid-state method. Powder X-ray diffraction, scanning electron microscope, and energy-dispersive X-ray spectrometer are employed to characterize the samples. The Mn-doped YMgTiO phosphors show the far-red emission at ∼715 nm, which is assigned to the E → A spin-forbidden transition of Mn. The temperature-dependent luminescent dynamics of Mn is described by a complete model associated with electron-lattice interaction and spin-orbit coupling. The noncontact optical thermometry of YMgTiO:Mn is discussed based on the fluorescence intensity ratio of thermally coupled anti-Stokes and Stokes sidebands of the efficient ∼715 nm far-red emission in the temperature range of 10-513 K. The maximum sensor sensitivity of YMgTiO:Mn is determined to be as high as 0.001 42 K at 153 K, which demonstrates potential applications for the optical thermometry at low-temperature environments.

Eu3+-doped antimonates show distinct luminescence spectra. 5D0 → 7F4, 5D0 → 7F1 and 5D0 → 7F0 are the dominant transitions for Eu3+-doped La3SbO7, Gd3SbO7 and Y3SbO7 respectively, due to different microstructures around the Eu3+ ions in the lattices.

A novel red emitting CsWOF:Mn phosphor was successfully synthesized by a two-step wet chemical method. The crystal structure, morphology, and elemental composition were confirmed by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS), respectively. The luminescence properties were investigated from emission, excitation and luminescence decay curves in the temperature region of 10-500 K. The application of non-contact optical thermometry of CsWOF:Mn based on the fluorescence intensity ratio (FIR) of the two coupled anti-Stokes and Stokes sidebands is discussed. The as-prepared CsWOF:Mn phosphor shows a bright narrow red emission at 632 nm under excitation by a blue lamp at 470 nm and it also presents a broad and yellow-white intrinsic tungstate emission (∼520 nm) under UV excitation. The mechanism of energy transfer from [WOF] (the sensitizer) to Mn (the activator) is discussed.

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Bluish-white-light-emitting diodes (BWLEDs) are designed based on the two-dimensional mixed halide perovskite (C6H5C2H4NH3)2PbCl2Br2 at room temperature. Bluish-white electroluminescence devices were fabricated by a spin-coating method. The BWLEDs can be turned on at 4.9 V and depict a maximum luminance of ∼70 cd/m2 at 7 V. Low and room temperature photoluminescence spectra show the coexistence of free exciton and self-trapped exciton luminescence in a deformable lattice. The strategy of achieving white electroluminescence (EL) from mixed halide perovskite reported here can be applied to other two-dimensional perovskites to increase the optoelectronic efficiency of the device in the future.