B-embedded disulfide-bridged π-conjugated compounds: structures and optical tuning

Area of Science:

• Organic Chemistry
• Materials Science
• Photophysics

Background:

• Disulfide-bridged π-conjugated molecules are explored for optoelectronic applications.
• Tuning electron donor groups influences molecular optical mechanisms.

Purpose of the Study:

• Synthesize and characterize novel B-embedded disulfide-bridged π-conjugated compounds.
• Investigate the optical mechanisms and performance of these compounds in organic light-emitting diodes (OLEDs).

Main Methods:

• Chemical synthesis of BS-CZ and BS-N compounds.
• Spectroscopic analysis (optical properties, singlet-triplet energy gap, FWHM).
• Time-dependent density functional theory (TD-DFT) calculations.
• Fabrication and characterization of OLED devices.

Main Results:

• BS-CZ displays multiple resonance thermal activation delayed fluorescence (MR-TADF) with a small ΔE_ST (0.16 eV) and narrow FWHM (33 nm).
• BS-N exhibits traditional fluorescence luminescence (FL) with a larger ΔE_ST (0.28 eV) and FWHM (57 nm).
• TD-DFT reveals local excited (LE) state in BS-CZ and charge transfer (CT) state in BS-N.
• BS-CZ as an emitting layer in OLEDs yields saturated blue emission (473 nm) with narrow FWHM (39 nm) and CIE coordinates (0.12, 0.21).

Conclusions:

• The study demonstrates a strategy for regulating optical mechanisms in B-embedded disulfide-bridged π-conjugated molecules.
• BS-CZ shows promising potential for efficient blue emission in OLED applications.
• Understanding structure-property relationships is key for designing advanced optoelectronic materials.