Amphoteric Chelating Ultrasmall Colloids for FAPbI₃ Nanodomains Enable Efficient Near-Infrared Light-Emitting Diodes.

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Perovskite light-emitting diodes (PeLEDs) offer high color purity and wide color gamut, but face challenges with polycrystalline domains and quantum dots.
• Polycrystalline domains exhibit weak carrier confinement, hindering radiative recombination.
• Quantum dots suffer from surface ligand-mediated carrier annihilation.

Purpose of the Study:

• To address limitations in current PeLED emitter forms.
• To develop a novel approach for controlling the in situ growth of FAPbI3 nanodomains.
• To enhance the performance and operational stability of PeLED devices.

Main Methods:

• Screening and application of an amphoteric agent, 2-(2-aminobenzoyl)benzoic acid (2-BA).
• Precise control over the in situ growth of FAPbI3 nanodomains with enhanced space confinement and preferred crystal orientation.
• Passivation of trap states on the transport-layer substrate using 2-BA.

Main Results:

• 2-BA facilitated bidentate chelation, forming ultrasmall perovskite colloids (<1 nm) and a smoother FAPbI3 emitting layer.
• Monodispersed and homogeneous nanodomain films were achieved.
• A near-infrared PeLED device demonstrated a champion efficiency exceeding 22% and enhanced T80 operational stability.

Conclusions:

• The amphoteric agent 2-BA effectively controls perovskite nanodomain growth, enhancing PeLED performance.
• The developed perovskite nanodomain film strategy offers a pathway to overcome current bottlenecks in PeLED technology.
• This approach is promising for achieving performance breakthroughs in PeLED devices across visible and infrared wavelengths.