Charge-Transfer Engineering in 0D/3D Rare-Earth Halide Heterostructures Enables Tunable and Efficient White...

Area of Science:

• Materials Science
• Solid-State Lighting
• Luminescent Materials

Background:

• Lead-free rare-earth metal halides are promising for solid-state white-light LEDs.
• Achieving efficient and spectrally tunable white emission remains a challenge.

Purpose of the Study:

• To design and synthesize a novel rare-earth halide heterostructure for high-performance white LEDs.
• To investigate the impact of in situ alloying and doping on luminescent properties.

Main Methods:

• An in situ alloying strategy using Ag+ ions to create a 0D/3D (Cs3LuCl6/Cs2AgLuCl6) heterostructure.
• Doping the heterostructure with Bi3+ ions.
• Characterization of photoluminescence, band alignment, and charge transfer dynamics.

Main Results:

• The heterostructure exhibits efficient interfacial charge transfer and boosted radiative recombination.
• Dual-peak self-trapped exciton emissions at 440 and 590 nm were observed.
• Photoluminescence quantum yield reached up to 92.12%.
• Correlated color temperature was continuously tunable by adjusting Bi3+ doping concentration.
• Phosphor-converted white LEDs demonstrated a color rendering index >90, excellent thermal stability, and 90% luminance retention after 100 hours.

Conclusions:

• The developed rare-earth halide heterostructure is a high-performance luminescent material for solid-state white lighting.
• The in situ alloying strategy and type-I band alignment are effective for enhancing radiative recombination.
• This work provides insights for designing advanced white light-emitting materials.