P3HT-Based Polymer Solar Cells with 8.25% Efficiency Enabled by a Matched Molecular Acceptor and Smart Green-Solvent...

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Developing efficient nonfullerene acceptors is crucial for advancing polymer solar cells (PSCs).
• Poly(3-hexylthiophene) (P3HT) is a widely studied donor material, but its performance is often limited by morphology control.
• Achieving optimal phase separation in the active layer is key for efficient exciton dissociation and charge transport.

Purpose of the Study:

• To design and synthesize a novel molecular acceptor, TrBTIC, for efficient P3HT-based PSCs.
• To investigate the effect of controlled prephase separation processing on the morphology and performance of P3HT:TrBTIC blend films.
• To establish a new processing strategy for high-performance P3HT-based PSCs.

Main Methods:

• Synthesis of a novel truxene-cored molecular acceptor (TrBTIC) by attaching BTIC units.
• Fabrication of PSCs using P3HT as the donor and TrBTIC as the acceptor.
• Controlled aging of the P3HT:TrBTIC blend in 1,2,4-trimethylbenzene (TMB) to tune phase separation.
• Morphological characterization of blend films (e.g., nanowire formation).
• Device performance testing and efficiency measurements.

Main Results:

• TrBTIC exhibits good solubility and energy level alignment with P3HT.
• Controlled aging of the blend film for 40 minutes resulted in uniform nanowire morphology and favorable interpenetrating networks.
• The optimized processing led to a significant increase in power conversion efficiency from 6.62% to a record 8.25% for P3HT-based PSCs.
• The new acceptor and processing method enable efficiencies exceeding 8%.

Conclusions:

• The novel TrBTIC acceptor effectively matches the P3HT donor.
• A promising processing technology involving controlled prephase separation enhances morphology and device performance.
• This work sets a new benchmark for P3HT-based PSCs and offers a viable strategy for future high-performance organic solar cells.