Optically Modulated Ultra-Broad-Band Warm White Emission in Mn2+-Doped (C6H18N2O2)PbBr4 Hybrid Metal Halide Phosphor

Finding new low-dimensional metal halides with broad-band emission is attracting interest in single-component phosphor for white light-emitting diodes (WLEDs). The full-spectrum white light still remains a challenge as found in the two-dimensional hybrid material (C₆H₁₈N₂O₂)PbBr₄ exhibiting the intrinsic free exciton (FE) and broad-band self-trap exciton (STE) emission upon 365 nm ultraviolet excitation, and a combined strategy has been proposed through doping the Mn²⁺ ions enabling a superposition of multiple emission centers toward the ultra-broad-band warm white light. The occupation of Mn²⁺ in (C₆H₁₈N₂O₂)PbBr₄ has been discussed, and optical investigations verify that the warm white-light emission of Mn²⁺-doped (C₆H₁₈N₂O₂)PbBr₄ originates from the coupling effects of the FE, STEs, and the ⁴T₁–⁶A₁ transition of the doped Mn²⁺. When the concentration of Mn²⁺ is 5%, the emission spectrum of the phosphor covers all visible-light areas with a full width at half maximum (FWHM) of about 230 nm. The high R_a (84.9) and warm light CCT (3577 K) values of the as-fabricated WLED lamp demonstrate that (C₆H₁₈N₂O₂)Pb_1–xMn_xBr₄ can be promising as single-component white-light phosphor in solid-state lighting. Our work could provide a new understanding and perspective about hybrid metal halides for designing superior phosphor toward single-component white emission.