4,5-Diazafluorene-Based Donor-Acceptor Small Molecules as Charge Trapping Elements for Tunable Nonvolatile Organic...

Area of Science:

• Organic electronics
• Materials science
• Nanotechnology

Background:

• Organic field-effect transistors (OFETs) are key components in electronic devices.
• Developing efficient charge storage materials is crucial for advanced memory applications.
• Triphenylamine (TPA) and diazafluorene (PDAF) are known for their electronic properties.

Purpose of the Study:

• To design and synthesize novel diazafluorene derivatives for OFET memory devices.
• To investigate the charge storage capabilities of these new molecular elements.
• To evaluate the performance of pentacene-based OFET memory devices incorporating these materials.

Main Methods:

• Synthesis of TPA(PDAF)n derivatives via Friedel-Crafts reaction.
• Fabrication of pentacene-based OFET memory devices using solution processing.
• Characterization of device performance, including charge trapping, memory window, and endurance.

Main Results:

• TPA(PDAF)3 exhibits single nanomolecular behavior due to its nonplanar structure.
• The material shows excellent hole-trapping ability with high density (4.55 × 10^12 cm^-2) and fast trapping speed (<20 ms).
• The optimized device achieved a large memory window (89 V), high ON/OFF ratio (2.85 × 10^7), and good charge retention (>10^4 s).

Conclusions:

• Diazafluorene-based donor-acceptor small molecules are promising for high-performance OFET memory.
• The designed TPA(PDAF)3 derivative enables efficient charge storage and retention.
• These materials offer tunable ambipolar memory behavior and reliable endurance, suitable for advanced memory applications.