High-n Phase Suppression for Efficient and Stable Blue Perovskite Light-Emitting Diodes

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Chemistry

Background:

• Quasi-2D perovskites show promise for light-emitting diodes (PeLEDs) due to excellent optical and electronic properties.
• Blue PeLEDs face challenges with inefficient energy transfer and performance issues stemming from mixed multidimensional phase distributions.

Purpose of the Study:

• To enhance the efficiency and performance of blue PeLEDs.
• To modulate the phase distribution in quasi-2D perovskites for improved blue light emission.

Main Methods:

• Introduction of transition metal salt, specifically zinc bromide (ZnBr2), into the perovskite structure.
• Utilizing ZnBr2 to suppress the nucleation of high n-phase perovskites, thereby controlling phase distribution.
• Investigating the effects of ZnBr2 on energy transfer pathways, energy level alignment, and non-radiative recombination.

Main Results:

• ZnBr2 effectively modulated phase distributions, shortening energy transfer paths crucial for blue emission.
• Improved energy level matching and reduced non-radiative recombination were observed with ZnBr2 incorporation.
• An efficient blue PeLED was fabricated, achieving a maximum external quantum efficiency (EQE) of 16.2% at 486 nm.

Conclusions:

• The addition of ZnBr2 offers a viable strategy for tuning the phase distribution in quasi-2D perovskites.
• This approach significantly enhances electroluminescence efficiency and performance in blue PeLEDs.
• The findings present a promising pathway toward developing highly efficient blue perovskite light-emitting diodes.