Elongated grain morphology for efficient and radiant NIR-II Sn-based perovskite light-emitting diodes

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Tin-based perovskite LEDs offer eco-friendly alternatives with potential for second near-infrared (NIR-II) emission.
• Challenges include self-doping and high hole mobility, leading to inefficient charge recombination and performance loss at high current densities.

Purpose of the Study:

• To enhance electron-hole injection and recombination dynamics in tin-based perovskite LEDs.
• To improve efficiency and reduce roll-off at high radiance levels.

Main Methods:

• A grain morphology modulation strategy using a growth regulator was employed.
• The regulator transformed perovskite grain structure from dendritic to island-like formations.
• This approach aimed to restrict excessive hole injection and confine recombination zones.

Main Results:

• Optimized devices achieved a 10.7% external quantum efficiency (EQE) at 963 nm NIR-II emission.
• A high radiance of 173 W sr^-1 m^-2 was reached.
• Low efficiency roll-off was observed, with 8.1% EQE maintained at 153.6 W sr^-1 m^-2.

Conclusions:

• Grain morphology modulation is an effective strategy for optimizing charge dynamics in tin-based perovskite LEDs.
• The developed devices show promising performance for high-radiance NIR-II emission applications.
• The approach successfully mitigates efficiency roll-off issues inherent in these materials.