Structure and luminescence behaviour of a novel red-emitting fluoroperovskite for display backlight application

In this work, we present a brand-new narrowband red-emitting fluoroperovskite via the introduction of Mn⁴⁺ into NaZnF₃ through a facile co-precipitation method at room temperature. The physicochemical properties of the fluoroperovskite such as crystal and electronic structures, morphology, and elemental composition, as well as its spectroscopic properties such as luminescence behaviours and optical performance were characterized and investigated in detail. Evidence shows that NaZnF₃:Mn⁴⁺ exhibits a uniform particulate shape with single-phase crystallinity. By virtue of the non-equivalent substitution and the [MnF₆] octahedral distortion in the fluoride host, sharp red emissions of phonon sidebands and the zero-phonon line upon blue light excitation are identified. Benefiting from the unique spectral feature, a wide colour gamut of 104.1% NTSC is achieved by coating β-SiAlON:Eu²⁺ and NaZnF₃:Mn⁴⁺ on an InGaN chip, indicating the potential use of the Mn⁴⁺ fluoroperovskite as a colour converter for display backlight application.