Optimizing Perovskite Surfaces to Enhance Post-Treatment for Efficient Blue Mixed-Halide Perovskite Light-emitting...

Area of Science:

• Materials Science
• Solid-State Chemistry
• Optoelectronics

Background:

• Halide postdeposition treatment is crucial for perovskite defect mitigation.
• Mixed-halide perovskites often suffer from halide heterogeneity after treatment, impacting performance.
• Surface and internal halide inhomogeneity compromises luminescence and spectral stability.

Purpose of the Study:

• To engineer blue mixed-halide 3D perovskites with acetate (Ac⁻)-rich surfaces.
• To optimize the post-treatment process for enhanced halide homogeneity.
• To improve luminescence performance and spectral stability in perovskite optoelectronics.

Main Methods:

• Surface engineering of blue mixed-halide 3D perovskites using acetate.
• Investigating the interaction between surface acetate ions and Pb²⁺ ions.
• Analyzing the impact of defect reduction on halide ion infiltration and surface reconstruction.
• Fabricating and characterizing blue mixed-halide 3D perovskite light-emitting diodes (PeLEDs).

Main Results:

• Acetate-rich surfaces significantly reduce halide vacancy defects during post-treatment.
• Minimized halide ion infiltration allows for improved surface reconstruction.
• Achieved a uniform mixed-halide perovskite phase with mild halide redistribution.
• Developed blue mixed-halide 3D PeLEDs with record external quantum efficiency (19.28% at 482 nm).
• Demonstrated narrowband and stable electroluminescence (FWHM < 16 nm).

Conclusions:

• Acetate surface engineering is an effective strategy for achieving halide homogeneity in mixed-halide perovskites.
• This method overcomes limitations of traditional post-treatment, enhancing device performance.
• The developed PeLEDs show promising potential for stable and efficient blue light emission.