Core/Shell ZnO/ZnS Nanoparticle Electron Transport Layers Enable Efficient All-Solution-Processed Perovskite...

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Solution-processed perovskite-based light-emitting diodes (PeLEDs) offer potential for low-cost, large-area displays.
• Fabrication challenges include perovskite layer deterioration during electron transport layer deposition.

Purpose of the Study:

• To develop a stable and efficient solution-processed electron transport layer for PeLEDs.
• To mitigate interfacial issues between the perovskite and electron transport layers.

Main Methods:

• Employing core/shell ZnO/ZnS nanoparticles as a solution-processed electron transport layer.
• Investigating the role of the ZnS shell in passivating ZnO core defects and reducing interfacial recombination.
• Fabricating PeLEDs based on quasi-2D PEA2Cs(n-1)PbnBr(3n+1) perovskite.

Main Results:

• The ZnS shell effectively passivates trap states on the ZnO core and removes hydroxyl groups.
• Core/shell ZnO/ZnS nanoparticles maintain high electron mobility while reducing the energy barrier for charge injection.
• Optimized PeLEDs demonstrate a peak luminance of 32,400 cd/m², external quantum efficiency of 10.3%, and 20-fold improved longevity compared to ZnO-based devices.

Conclusions:

• Core/shell ZnO/ZnS nanoparticles represent a superior electron transport layer for solution-processed PeLEDs.
• This approach significantly enhances device performance and operational stability.
• The findings pave the way for advanced, cost-effective perovskite display technologies.