Red Phosphorescent Carbon Quantum Dot Organic Framework-Based Electroluminescent Light-Emitting Diodes Exceeding 5%...

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Carbon quantum dots (CQDs) are promising for lighting due to stability and eco-friendliness.
• Fluorescent CQDs have limited external quantum efficiency (EQE) below 5% due to spin-forbidden triplet transitions.
• Efficient red emission is crucial for full-color displays, but challenging for CQDs.

Purpose of the Study:

• To synthesize red phosphorescent carbon quantum dot organic frameworks (CDOFs).
• To achieve high-efficiency red phosphorescent electroluminescent light-emitting diodes (LEDs).
• To overcome the efficiency limitations of fluorescent CQDs for display applications.

Main Methods:

• Synthesis of red phosphorescent carbon quantum dot organic frameworks (CDOFs).
• Fabrication and characterization of electroluminescent LEDs using CDOFs.
• Measurement of photoluminescence quantum yield, luminance, and EQE.

Main Results:

• Achieved red phosphorescent CDOFs with a quantum yield of up to 42.3%.
• Demonstrated high-efficiency red phosphorescent electroluminescent LEDs with a maximum luminance of 1818 cd m^-2.
• Attained an EQE of 5.6% for the red phosphorescent LEDs.

Conclusions:

• Phosphorescent CQDs, specifically CDOFs, can overcome the efficiency limitations of fluorescent CQDs.
• The developed CDOFs enable high-performance red electroluminescent LEDs.
• This work opens new avenues for high-performance CQD-based electroluminescent devices.