Defect Passivation for Red Perovskite Light-Emitting Diodes with Improved Brightness and Stability

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Physics

Background:

• Efficient and stable red perovskite light-emitting diodes (PeLEDs) are crucial for full-color displays and lighting applications.
• Current red PeLEDs often suffer from low brightness due to phase separation and poor charge transport.
• Existing approaches using mixed-halide or low-dimensional perovskites have not fully overcome these performance limitations.

Purpose of the Study:

• To demonstrate high-performance red PeLEDs utilizing three-dimensional (3D) mixed-halide perovskites.
• To improve device stability and efficiency through defect passivation.
• To achieve record-breaking brightness and operational stability in red PeLEDs.

Main Methods:

• Fabrication of red PeLEDs using 3D mixed-halide perovskite materials.
• Passivation of perovskite film defects using 5-aminovaleric acid.
• Characterization of device performance, including emission spectra, external quantum efficiency, luminance, and operational stability.

Main Results:

• Red PeLEDs with an emission peak at 690 nm achieved an external quantum efficiency of 8.7% and a luminance of 1408 cd m^-2.
• Tuning the emission peak to 662 nm resulted in a maximum luminance of 8547 cd m^-2, setting a new benchmark for red PeLED brightness.
• The developed LEDs demonstrated a half-life of up to 8 hours under a high current density (100 mA cm^-2), significantly outperforming previous literature.

Conclusions:

• Defect passivation with 5-aminovaleric acid effectively enhances the performance of 3D mixed-halide red PeLEDs.
• The demonstrated PeLEDs exhibit state-of-the-art brightness and stability, paving the way for practical applications in displays and lighting.
• This work provides a viable strategy for developing efficient and stable red electroluminescent devices based on perovskite materials.