Tailor-made rylene arrays for high performance n-channel semiconductors

Area of Science:

• Materials Science
• Organic Chemistry
• Optoelectronics

Background:

• Rylene dyes, based on naphthalene units, are crucial for π-functional materials in optoelectronics.
• Perylene diimide (PDI) and naphthalene diimide (NDI) derivatives offer enhanced solubility, stability, and electron-transporting properties.
• Extending π-conjugation in rylene diimides typically leads to bathochromic shifts and increased extinction coefficients.

Purpose of the Study:

• To design and synthesize novel, laterally expanded rylene dyes.
• To achieve high-performance n-channel organic semiconducting materials through innovative synthetic strategies.
• To explore structure-property relationships in these new materials for optoelectronic applications.

Main Methods:

• Utilized homocoupling and cross-coupling reactions of core-functionalized PDIs and NDIs.
• Employed transition-metal mediated coupling reactions and C-H transformations for synthesis.
• Investigated both bay- and nonbay-functionalization for lateral expansion and construction of hybrid rylene arrays.

Main Results:

• Successfully synthesized singly linked, doubly linked, and fully conjugated triply linked oligoPDIs.
• Demonstrated significant red-shifts in absorption maxima and positive shifts in redox potentials.
• Observed decreased energy gaps and increased electron-accepting abilities due to π-system expansion.

Conclusions:

• Laterally expanded rylene dyes exhibit exceptional n-channel semiconductor performance.
• These materials are promising for high-performance organic field-effect transistors (OFETs).
• They are competitive candidates for non-fullerene acceptors in high-efficiency organic photovoltaic devices (OPVs).