Efficient Narrow-Band Green Light-Emitting Hybrid Halides for Wide Color Gamut Display

Phosphors with narrow-band emission are in great demand for liquid crystal display backlighting applications. In this work, four zero-dimensional Mn 2+ -based organic–inorganic metal halides (OIMHs), (C 13 H 26 N) 3 MnBr 4 ·Br, (C 13 H 26 N) 2 MnCl 4, and (C 7 H 18 N) 2 MnX 4 (X = Cl, Br), were synthesized, and their crystal structures were solved. Under blue-light excitation, all of the materials exhibited bright narrow-band green luminescence centered at 515–525 nm with high photoluminescence quantum yields (PLQYs). Significantly, (C 13 H 26 N) 3 MnBr 4 ·Br and (C 13 H 26 N) 2 MnCl 4 exhibited small full width at half-maximum (FWHM) values of 43 and 48 nm with PLQYs of 77.8 and 79.3% at room temperature, respectively. Compared with the reported luminescent OIMHs, ultrahigh thermal quenching temperatures were observed, and at 420 K, emission intensities of (C 13 H 26 N) 3 MnBr 4 ·Br and (C 13 H 26 N) 2 MnCl 4, remained 82.7 and 64.2% of those at room temperature, respectively. The rigid environment provided by the C 13 H 26 N + cation has a strong confinement effect on the [MnX 4 ] 2– tetrahedra, leading to a narrower FWHM and higher thermal quenching temperature. Finally, (C 13 H 26 N) 3 MnBr 4 ·Br was combined with commercial phosphors to fabricate light-emitting diodes (LEDs) with a wide color gamut of up to 113% NTSC (National Television System Committee). This work provides a reference for designing the OIMHs for liquid crystal display LEDs by tuning the organic cations.