Achieving Single‐Phased Full Visible Spectrum Broadband White Emission in Ag⁺, Bi 3 ⁺, and Sb 3 ⁺ Tri‐Doped Cs₂NaLuCl₆ Double Perovskite Phosphor

Abstract Single‐phased white‐light phosphors can overcome the issues of re‐absorption and color drift in phosphor‐converted white light‐emitting diodes, while achieving the high efficiency full‐spectrum white light phosphors remains an inescapability challenge toward the high‐quality illumination. Herein, the single‐phased full visible spectrum white phosphors are developed by doping Bi 3+ and Sb 3+ into Cs 2 NaLuCl 6 : Ag + . The Cs 2 NaLuCl 6 : 5%Ag + , 5%Bi 3+ , 1%Sb 3+ performs an ultra‐wide white emission covering the whole visible light region (400–800 nm) with about 305 nm full width at half maximum and 70% quantum yield, whose spectrum is consisted of blue band of Sb 3+ ( 3 P 1 → 1 S 0 ) at 455 nm and orange‐red band of Ag + ( 3 D 1 → 1 S 0 ) at 611 nm. The warm white LED with low color temperature (3656 K) and high color rending index (95) can be fabricated by the combination of 365 nm chip with the prepared phosphors. Meanwhile the electroluminescence spectrum of LED possesses high spectrum resemblance with absorption band of photosynthetic pigments. The prepared white light phosphors exhibit great application potential in white light and plant growth illumination fields.