Efficiency-Tunable Single-Component White-Light Emission Realized in Hybrid Halides Through Metal Co-Occupation

Organic-inorganic hybrid metal halides have attracted widespread attention as emerging optoelectronic materials, especially in solid-state lighting, where they can be used as single-component white-light phosphors for white light-emitting diodes. Herein, we have successfully synthesized a zero-dimensional (0D) organic-inorganic hybrid mixed-metal halide (Bmpip)₂Pb_xSn_1-xBr₄ (0 < x < 1, Bmpip⁺ = 1-butyl-1-methyl-piperidinium, C₁₀H₂₂N⁺) that crystallizes in a monoclinic system in the C2/c space group. Pb²⁺ and Sn²⁺ form a four-coordinate seesaw structure separated by organic cations forming a 0D structure. For different excitation wavelengths, (Bmpip)₂Pb_xSn_1-xBr₄ (0 < x < 1) exhibits double-peaked emission at 470 and 670 nm. The emission color of (Bmpip)₂Pb_xSn_1-xBr₄ can be easily tuned from orange-red to blue by adjusting the Pb/Sn molar ratio or excitation wavelength. Representatively, (Bmpip)₂Pb_0.16Sn_0.84Br₄ exhibits approximately white-light emission with high photoluminescence quantum yield up to 39%. Interestingly, the color of (Bmpip)₂Pb_xSn_1-xBr₄ can also be easily tuned by temperature, promising its potential for application in temperature measurement and indication. Phosphor-converted light-emitting diodes are fabricated by combining (Bmpip)₂Pb_xSn_1-xBr₄ and 365 nm near-UV LED chips and exhibit high-quality light output.