A-D-A Type Small Molecules Based on Boron Dipyrromethene for Solution-Processed Organic Solar Cells

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Boron dipyrromethene (BODIPY) dyes possess advantageous properties like high absorption, stability, and facile synthesis.
• These characteristics make BODIPY dyes promising candidates for organic solar cell (OSC) applications.

Purpose of the Study:

• To synthesize novel A-D-A small molecules incorporating BODIPY acceptor units.
• To investigate the structure-property relationships of these molecules in bulk heterojunction organic solar cells (BHJ OSCs).

Main Methods:

• Synthesis of three A-D-A small molecules: BDTT-BODIPY, FL-BODIPY, and TT-BODIPY.
• Structural modification by conjugating BODIPY units to different donor cores (BDTT, FL, TT).
• Fabrication and performance testing of BHJ OSCs using [6,6]-phenyl C71 -butyric acid methyl ester (PC71 BM) as the acceptor.

Main Results:

• BDTT-BODIPY, FL-BODIPY, and TT-BODIPY were successfully synthesized.
• BHJ OSCs based on these donors achieved power conversion efficiencies (PCEs) of 4.75%, 1.51%, and 1.67%, respectively.
• Structural variations significantly influenced the performance of the OSCs.

Conclusions:

• The synthesized BODIPY-based A-D-A molecules show potential for BHJ OSC applications.
• The BDTT-BODIPY molecule demonstrated superior performance, highlighting the importance of donor core selection.
• Further structural optimization could lead to enhanced efficiencies in BODIPY-based organic solar cells.