Boosting the Efficiency of NiO-Based Perovskite Light-Emitting Diodes by Interface Engineering

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Nickel oxide (NiO) is a cost-effective and stable hole-transporting material for perovskite light-emitting diodes (PeLEDs).
• Current limitations in NiO-based PeLEDs include inefficient hole injection and exciton quenching at the NiO-perovskite interface, hindering electroluminescence efficiency.
• Addressing these interfacial issues is crucial for advancing PeLED performance.

Purpose of the Study:

• To develop a novel interfacial engineering strategy to enhance the performance of NiO-based PeLEDs.
• To overcome the challenges of inefficient hole injection and exciton quenching at the NiO-perovskite interface.
• To improve the external quantum efficiency (EQE) of perovskite LEDs.

Main Methods:

• Interfacial engineering using sodium dodecyl sulfate-oxygen plasma (SDS-OP) treatment on NiO films.
• Modification of NiO work function through the formation of a surface dipole via SDS-OP treatment.
• Passivation of perovskite surface trap states and suppression of exciton quenching using the SDS-OP layer.

Main Results:

• SDS-OP treatment significantly increased the work function of NiO from 4.23 eV to 4.85 eV, facilitating efficient hole injection.
• The SDS-OP layer effectively passivated trap states on perovskite films and suppressed exciton quenching.
• External quantum efficiency (EQE) of CsPbBr3 LEDs improved from 0.052% to 2.5%.
• EQE of FAPbBr3 nanocrystal LEDs increased from 5.6% to 7.6%.

Conclusions:

• The SDS-OP interfacial engineering method successfully addresses key limitations in NiO-based PeLEDs.
• This approach enables efficient hole injection and reduces nonradiative recombination at the NiO-perovskite interface.
• The demonstrated strategy offers a promising pathway for developing high-efficiency perovskite optoelectronic devices.