Enhancing Sky-Blue Perovskite Light-Emitting Diode Performance through Guanidinium-Based Dual-Functional Molecular...

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Perovskite light-emitting diodes (PeLEDs) offer high efficiency and tunable emission for displays and lighting.
• Achieving stable and efficient blue emission in PeLEDs is challenging due to issues like poor phase purity and trap density.

Purpose of the Study:

• To develop a dual-functional molecular engineering strategy for enhancing blue PeLED performance.
• To utilize 4-guanidinobenzoic acid hydrochloride (GBAC) as both an interfacial layer and a bulk additive.

Main Methods:

• GBAC was applied as a buried interfacial layer to improve film morphology and energy level alignment.
• GBAC was incorporated as a bulk additive to passivate Pb2+ trap states and control perovskite phase formation.
• Device performance was evaluated based on spectral stability, turn-on voltage, and external quantum efficiency.

Main Results:

• The interfacial GBAC layer improved surface wettability, precursor spreading, film crystallinity, and energy level alignment.
• The bulk GBAC additive passivated Pb2+ traps and promoted the formation of desired perovskite phases, enhancing energy funneling.
• Devices with dual GBAC treatment showed improved spectral stability, reduced turn-on voltage, and achieved a sky-blue external quantum efficiency of 10.6%.

Conclusions:

• Dual-functional molecular engineering with GBAC is an effective strategy for overcoming challenges in blue PeLEDs.
• This approach significantly enhances the efficiency and stability of sky-blue PeLEDs, demonstrating a >60% improvement.
• GBAC holds promise for advancing next-generation display and lighting technologies.