Grain engineering for efficient near-infrared perovskite light-emitting diodes

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Physics

Background:

• Metal halide perovskites are promising for near-infrared light-emitting diodes (LEDs), outperforming organic and quantum-dot alternatives.
• Current perovskite LEDs lag behind expensive III-V semiconductor devices in external quantum efficiency (EQE) and brightness.
• Controlling grain growth and nanoscale morphology is critical for improving perovskite LED performance.

Purpose of the Study:

• To develop a grain engineering methodology for enhancing perovskite LED performance.
• To improve light outcoupling efficiency and defect passivation in near-infrared perovskite LEDs.
• To enable cost-effective, high-performance near-infrared light sources.

Main Methods:

• Combined solvent engineering for precise control over grain size and distribution.
• Constructed 2D/3D heterostructures with a conjugated cation for defect reduction.
• Investigated the impact of these methods on light outcoupling and radiative recombination.

Main Results:

• Solvent engineering increased light outcoupling efficiency to approximately 40%.
• 2D/3D heterostructures reduced defect densities and accelerated radiative recombination.
• Achieved a peak external quantum efficiency of 31.4% and a maximum brightness of 929 W sr^-1 m^-2 in near-infrared perovskite LEDs.

Conclusions:

• The grain engineering methodology effectively enhances perovskite LED performance.
• Perovskite LEDs demonstrate potential as cost-effective, high-brightness near-infrared light sources.
• This approach addresses key limitations hindering the practical application of perovskite optoelectronics.