p-π Conjugated Polymers Based on Stable Triarylborane with n-Type Behavior in Optoelectronic Devices

Area of Science:

• Materials Science
• Polymer Chemistry
• Organic Electronics

Background:

• Conjugated polymers are crucial for organic electronics.
• Tuning electronic structure via p-π conjugation with heteroatoms is key.
• Electron-deficient polymers are needed for n-type applications.

Purpose of the Study:

• To synthesize highly electron-deficient p-π conjugated polymers based on triarylboranes.
• To demonstrate their n-type semiconductor behavior.
• To explore their application in photovoltaic devices.

Main Methods:

• Incorporation of [2,4,6-tris(trifluoromethyl)phenyl]di(thien-2-yl)borane (FBDT) units.
• Alternating FBDT with electron-deficient isoindigo (IID) or pyridine-flanked diketopyrrolopyrrole (DPPPy) units.
• Fabrication and characterization of all-polymer solar cells.

Main Results:

• Achieved low-lying lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energy levels.
• Demonstrated high electron mobilities and broad visible light absorption.
• Attained power conversion efficiencies up to 2.83% in all-polymer solar cells.

Conclusions:

• Unambiguously proved the n-type semiconductor behavior of triarylborane-based conjugated polymers.
• Established the viability of these polymers as electron acceptors in solar cells.
• Highlighted the potential of triarylborane units for designing advanced organic electronic materials.