Efficient Red/Green Inverted Quantum-Dot Light-Emitting Diodes Enabled by Bilateral Heterojunction Charge-Generation...

Area of Science:

• Optoelectronics
• Materials Science
• Solid State Physics

Background:

• Inverted quantum-dot light-emitting diodes (QLEDs) face challenges with inefficient charge injection and interfacial energy barriers.
• These limitations hinder the overall performance and efficiency of QLED devices.

Purpose of the Study:

• To develop an improved charge-generation layer (CGL) architecture for inverted QLEDs.
• To enhance carrier injection balance and reduce interfacial energy barriers.
• To achieve higher efficiencies and improved operational stability in red and green inverted QLEDs.

Main Methods:

• Proposed a novel bilateral charge-generation layer (CGL) architecture.
• Integrated two complementary heterojunctions: PEDOT:PSS/ZnO and TAPC/HAT-CN.
• Decoupled carrier supply from electrodes for balanced injection into the quantum-dot emissive layer.

Main Results:

• Achieved a record external quantum efficiency (EQE) of 30.8% for red emission and 20.1% for green emission.
• Attained current efficiencies of 40.8 cd A^-1 (red) and 88.1 cd A^-1 (green).
• Demonstrated extended operational stability with extrapolated T₅₀ lifetimes exceeding 36,000 hours at 100 cd m^-2.

Conclusions:

• The bilateral CGL architecture significantly enhances efficiency and stability in inverted QLEDs compared to unilateral designs.
• This work provides a practical design strategy for developing high-performance and stable inverted QLEDs.
• Offers valuable insights for the advancement of emerging optoelectronic technologies.