A Rigid Polymer Donor Based on a Simple Benzodithiophene-Thiazole Backbone for Organic Photovoltaics

Area of Science:

• Materials Science
• Organic Electronics
• Polymer Chemistry

Background:

• Organic photovoltaics (OPVs) require efficient polymer donors for high performance.
• Controlling polymer backbone conformation and intermolecular interactions is crucial for OPV efficiency.

Purpose of the Study:

• To synthesize and characterize a novel polymer donor, PBDTTz, for OPVs.
• To investigate the effect of thiazole incorporation on polymer structure and OPV performance.

Main Methods:

• Synthesis of PBDTTz polymer with a benzo[1,2-b:4,5-b']dithiophene-thiazole backbone.
• Fabrication and testing of organic photovoltaic devices using PBDTTz and L8-BO.
• Analysis of polymer structure, energy levels, and blend morphology.

Main Results:

• PBDTTz exhibited a rigid, coplanar backbone due to intramolecular N···S interactions.
• The polymer showed enhanced intermolecular π-π stacking and improved blend morphology.
• Optimized OPVs with PBDTTz achieved a power conversion efficiency of 15.3%.

Conclusions:

• Thiazole incorporation is an effective strategy for controlling polymer donor properties in OPVs.
• PBDTTz offers a straightforward route to high-performance polymer donors.
• The study demonstrates the potential of thiazole-based polymers for efficient organic solar cells.