The Role of Intermolecular Interaction on Aggregation-Induced Emission Phenomenon and OLED Performance

Area of Science:

• Materials Science
• Organic Chemistry
• Photophysics

Background:

• Aggregation-induced emission (AIE) is a photophysical phenomenon where luminescence is enhanced in aggregate or solid states.
• Organic light-emitting diodes (OLEDs) are crucial for display and lighting technologies, with performance heavily influenced by material properties.

Purpose of the Study:

• To investigate the impact of intermolecular interactions on AIE properties.
• To design and synthesize novel compounds exhibiting AIE.
• To evaluate the performance of these compounds in OLED devices.

Main Methods:

• Density Functional Theory (DFT) for molecular design.
• Chemical synthesis of target compounds.
• Spectroscopic analysis (optical, electrochemical) to characterize AIE properties.
• Fabrication and testing of OLED devices using a hybrid spin-coating/evaporation method.

Main Results:

• Synthesized compounds with a (-CH=C(CN)(COOR)) moiety showed strong AIE characteristics.
• Emission efficiency rapidly increased with aggregation, controllable via substituents.
• Intermolecular interactions were tuned to control the emitted light wavelength.
• Fabricated OLEDs demonstrated green-blueish electroluminescence with a maximum luminance of 25 cd m⁻² and 2% external quantum efficiency (EQE).

Conclusions:

• Intermolecular interactions play a significant role in modulating AIE phenomena.
• Tailoring molecular substituents offers a method to control AIE and emission color.
• The synthesized compounds are promising for applications in OLEDs.