Probing disorder in 2CzPN using core and valence states

Area of Science:

• Materials Science
• Organic Electronics
• Quantum Chemistry

Background:

• Thermally activated delayed fluorescence (TADF) emitters are crucial for efficient, eco-friendly OLEDs.
• Disordered thin films in devices introduce environmental and structural variations affecting TADF emitter performance.
• Understanding these variations is key to designing improved TADF materials.

Purpose of the Study:

• To investigate the impact of molecular disorder on core and valence electronic states of TADF emitters.
• To assess the sensitivity of different electronic states to structural changes, such as torsion angle variations.
• To validate a computational approach for interpreting experimental spectra of complex organic molecules.

Main Methods:

• Density Functional Theory (DFT) simulations of gas-phase 2CzPN molecules with varying disorder.
• X-ray photoelectron spectroscopy (XPS) experiments.
• Comparative analysis of simulated and experimental core and valence electronic states.

Main Results:

• Simulated electronic structures under varying disorder levels correlate well with experimental XPS data.
• The study quantifies the sensitivity of core and valence states to molecular parameter fluctuations.
• The computational method proves effective for interpreting complex spectra of large aromatic molecules.

Conclusions:

• Molecular disorder significantly influences the electronic properties of TADF emitters like 2CzPN.
• The combined DFT and XPS approach accurately models and interprets experimental observations.
• This work provides a framework for designing more stable and efficient TADF materials for OLED applications.