Mn4+-activated K2SiF6 phosphors for use in light emitting diode (LED) applications have recently attracted a great deal of attention since they exhibit an advantage over conventional wide band-type red-light-emitting phosphors.

Phosphors that exhibit a narrow red emission are particularly interesting due to the advantage of providing a more extensive color gamut and better rendering in LED applications such as displays and solid‐state lighting. Although some Eu2+‐activated nitridosilicates have been discovered in this regard, K2SiF6:Mn4+ phosphors are the only option in actual LED applications thus far. We discovered a novel phosphor, K3SiF7:Mn4+, with P4/mbm symmetry. The luminescent properties of K3SiF7:Mn4+ are almost identical to those of the K2SiF6:Mn4+ phosphor, but its materials identity is distinct due to a completely different crystallographic structure, which leads to reduced decay time. The fast decay is one of the most serious disadvantages of existing K2SiF6:Mn4+ phosphors. The K3SiF7:Mn4+ phosphor was examined in comparison to the K2SiF6:Mn4+ via density functional theory calculation, Rietveld refinement, X‐ray photoelectron spectroscopy, X‐ray absorption near‐edge structure spectroscopy, and time‐resolved photoluminescence.

Correction for ‘Radiative and non-radiative decay rate of K2SiF6:Mn4+ phosphors’ by Minseuk Kim et al., J. Mater. Chem. C, 2015, 3, 5484–5489.