Bright and Stable Red Perovskite LEDs under High Current Densities

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Physics

Background:

• Perovskite LEDs (PeLEDs) are a promising next-generation light-emitting technology.
• Existing visible PeLEDs suffer from short operational lifetimes (<100 h) at high current densities (>10 mA cm⁻²), hindering applications in solid-state lighting and AR/VR.
• Mixed-halide perovskite emitters face challenges like halide segregation and spectral instability, further limiting device performance.

Purpose of the Study:

• To demonstrate bright and stable red PeLEDs based on mixed-halide perovskites.
• To overcome the limitations of operational lifetime and spectral instability in visible PeLEDs.
• To achieve record operational stability and brightness for red PeLEDs under high current densities.

Main Methods:

• Fabrication of red PeLEDs using mixed-halide perovskite emitters.
• Introduction of sulfonamide as a dipolar molecular stabilizer.
• Characterization of device performance, including operational lifetime (T50) and luminance.

Main Results:

• Achieved operational lifetimes (T50) of up to ~357 h at current densities ≥25 mA cm⁻², a record for visible PeLEDs under high current densities.
• Demonstrated intense and stable emission with a maximum luminance of 28,870 cd m⁻² (record-high for red PeLEDs).
• Sulfonamide effectively suppressed halide segregation and migration, enhancing device stability and brightness.

Conclusions:

• The developed red PeLEDs exhibit unprecedented operational stability and brightness.
• Sulfonamide acts as a crucial stabilizer, mitigating halide segregation and improving device longevity.
• These findings represent a significant advancement towards practical, high-performance PeLEDs for emerging applications.