The formation mechanism of red phosphor K2SiF6:Mn4+ free of manganese oxides has been discussed based on detailed experimental results. Significant improvements in the luminescence efficiency make it a good candidate for applications in “warm” white LEDs.

A novel red phosphor Li3Na3Ga2F12:Mn4+was obtained at room temperature and its luminescence efficiency has been improved by optimizing the synthetic process.

A crucial challenge is to develop an in situ passivation treatment strategy for CsPbX3 (CPX, X=Cl, Br, and I) quantum dots (QDs) and simultaneously retain their luminous efficiency and wavelength. Here, a facile method to significantly improve the stability of the CPX QDs via in situ crystallization with the synergistic effect of 4‐bromo‐butyric acid (BBA) and oleylamine (OLA) in polar solvents including aqueous solution and a possible fundamental mechanism are proposed. Monodispersed CsPbBr3 (CPB) QDs obtained in water show high photoluminescence quantum yields (PLQYs) of 86.4 % and their PL features of CPB QDs have no significant change after being dispersed in aqueous solution for 96 h, which implies the structure of CPB QDs is unchanged. The results provide a viable design strategy to synthesize all‐inorganic perovskite CPX QDs with strong stability against the attack of polar solvents and shed more light on their surface chemistry.

Single-component white light emitters are particularly attractive for fabricating economical solid-state devices for display and lighting. Herein, an efficient white light with photoluminescence quantum yields approaching 98% has been obtained in Mn2+ and Pb2+ co-doped Cs7Cd3Br13 crystals. The quantified bonding and nonbonding characters calculated by the crystal orbital Hamilton population analysis demonstrate that the Mn2+ and Pb2+ occupy preferentially in the [CdBr4]2– tetrahedrons rather than the [CdBr6]4– octahedrons in Cs7Cd3Br13. According to the PL spectral characteristic and the theoretical results, the broadband white light emission from Cs7Cd3Br13:Pb2+,Mn2+ crystals is ascribed to the multiple PL origins, i.e., the first self-trapped exciton (STE1) from the intrinsic trapping states of host lattice Cs7Cd3Br13, the d–d transition of Mn2+, and the second self-trapped exciton (STE2) induced by the introduction of Pb2+, respectively. The results calculated by density functional theory reveal that the incorporation of Mn2+ and Pb2+ has significantly improved the thermodynamic stability of the Cs7Cd3Br13 structure with lower defect formation energies, which is verified by the experimental observation in the temperature-dependent PL spectra of the emitting crystals. The findings here provide a new perspective for a single-component white light via creating multiple PL centers in a single matrix as well as help in the elucidation of the preferential site occupancy mechanism of the dopants in different symmetrical units.

A novel red phosphor composed of Mn4+-activated oxyfluoroniobate BaNbOF5was obtained at room temperature in air. The as-prepared phosphor showed a broad and intense absorption in the blue-light region and a bright red luminescence with a color purity of 97.7%.

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A novel red fluoride phosphor NKSF:Mn was obtained at room temperature by controlling the ratio of NaF to KF. The chromaticity coordinates of phosphor NKSF:Mn are very close to the CIE coordinates of ideal red ascribed to the contribution of particularly strong zero-phonon lines.

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