Tuning the Transparency and Exciton Transition of D-π-A-π-D Type Small Molecules

Area of Science:

• Materials Science
• Organic Electronics
• Computational Chemistry

Background:

• Organic small molecules offer tunable optical properties for semitransparent optoelectronics.
• Designing these materials is complex due to sensitivity to structural changes and vast design space.

Purpose of the Study:

• To establish an efficient material discovery workflow for customized, highly transparent conjugated organic small molecules.
• To create small molecules with adjustable transparency windows for optoelectronic applications.

Main Methods:

• Literature-based preselection of molecules with D-π-A-π-D architecture.
• Time-dependent density-functional theory (TDDFT) calculations for absorption spectra and energy levels.
• Synthesis and characterization of selected organic small molecules.

Main Results:

• Identified 54 small molecules with D-π-A-π-D architecture.
• Calculated theoretical absorption spectra and energy levels for all identified molecules.
• Synthesized 24 molecules exhibiting selective UV/NIR absorption and a broad visible optical window; 6 showed the broadest windows.

Conclusions:

• The developed workflow effectively designs organic small molecules with tunable transparency.
• Six synthesized molecules demonstrate exceptional selective absorption and broad optical windows.
• This approach provides valuable insights for discovering highly transparent conjugated organic small molecules.