Fully Fused Indacenodithiophene-Centered Small-Molecule n-Type Semiconductors for High-Performance Organic...

Area of Science:

• Materials Science
• Organic Electronics

Background:

• Developing novel n-type organic semiconductors is crucial for advancing organic electronics due to their scarcity compared to p-type materials.
• N-type semiconductors are essential components in various organic electronic devices, including transistors and solar cells.

Purpose of the Study:

• To synthesize novel n-type organic semiconductors with a fully fused conjugated backbone.
• To investigate the performance of these new materials in organic field-effect transistors (OFETs) and organic solar cells (OSCs).

Main Methods:

• A new synthetic strategy involving Knoevenagel condensation and intramolecular cyclization was employed.
• Two new molecules, DFA1 and DFA2, were synthesized based on an indacenodithiophene core.
• Solution-processed OFETs and ternary organic solar cells were fabricated and characterized.

Main Results:

• The synthesized compounds, DFA1 and DFA2, exhibited unipolar n-type transport characteristics in OFETs.
• DFA1-based OFETs showed an electron mobility of approximately 0.10 cm²/Vs.
• Incorporating DFA1 into ternary organic solar cells (PM6:L8-BO:DFA1) resulted in a high power conversion efficiency of 19.2%.

Conclusions:

• The study presents a viable new pathway for the molecular engineering of n-type organic semiconductors.
• The developed materials demonstrate significant potential for applications in high-performance organic electronics.
• This research contributes to overcoming the scarcity of effective n-type organic semiconductor materials.