Efficient Blue Perovskite LEDs via Bottom-Up Charge Manipulation for Solution-Processed Active-Matrix Displays

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Physics

Background:

• Perovskite light-emitting diodes (PeLEDs) show promise for next-generation displays due to excellent optoelectronic properties, solution processability, and cost-effectiveness.
• Achieving highly efficient blue PeLEDs remains a significant challenge in the field.

Purpose of the Study:

• To develop a strategy for precise charge manipulation in blue perovskites to enhance radiative recombination efficiency.
• To improve the performance and stability of blue PeLEDs for display applications.

Main Methods:

• A bottom-up strategy was employed using 1,3-bis(N-carbazolyl)benzene as a hole transport layer to improve hole injection and suppress reverse electron transport.
• A fluorinated ester additive was used to control perovskite crystallization, promoting reduced-dimensional phases and minimizing nonradiative recombination.
• The developed blue PeLEDs were integrated with thin-film transistor circuits for active-matrix display fabrication.

Main Results:

• The engineered blue PeLEDs achieved a record external quantum efficiency of 25.87%, the highest reported for one-step-prepared blue perovskite films.
• The strategy effectively improved hole injection, suppressed reverse electron transport, and reduced exciton quenching.
• The integration resulted in solution-processed active-matrix perovskite displays with sharp and uniform patterning.

Conclusions:

• The study presents a comprehensive pathway for advancing blue PeLEDs towards high-performance display applications.
• The developed methods significantly enhance radiative recombination efficiency and device performance.
• This work paves the way for the commercialization of efficient and stable blue PeLED displays.