Acceleration of radiative recombination for efficient perovskite LEDs

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Physics

Background:

• Thin-film light-emitting diodes (LEDs) require higher efficiency and brightness for displays and lighting.
• Three-dimensional (3D) perovskites offer high charge mobility and low quantum efficiency droop, making them promising for LED applications.
• Current 3D perovskites are limited by slow radiative recombination, capping photoluminescence quantum efficiencies (PLQEs) below 80% and external quantum efficiencies (EQEs) below 25%.

Purpose of the Study:

• To develop a method for creating highly efficient 3D perovskites for advanced LED applications.
• To overcome the limitations of slow radiative recombination in existing 3D perovskite materials.
• To enhance the brightness and efficiency of perovskite-based LEDs.

Main Methods:

• A novel dual-additive crystallization method was employed to synthesize 3D perovskite films.
• The method focused on promoting the formation of tetragonal FAPbI3 perovskite.
• Characterization of photoluminescence quantum efficiency (PLQE) and external quantum efficiency (EQE) of the resulting perovskite LEDs.

Main Results:

• Achieved an exceptional PLQE of 96% in the synthesized 3D perovskites.
• The dual-additive method facilitated the formation of tetragonal FAPbI3, accelerating radiative recombination due to high exciton binding energy.
• Demonstrated perovskite LEDs with a record peak EQE of 32.0%.
• Maintained high efficiency, with EQE remaining above 30.0% at a current density of 100 mA cm⁻².

Conclusions:

• The dual-additive crystallization method significantly enhances the efficiency of 3D perovskites.
• This approach effectively addresses the slow radiative recombination issue, leading to improved LED performance.
• The developed perovskites represent a significant advancement for high-efficiency and high-brightness perovskite LED technology.