Efficient and Stable All-Polymer Solar Cells Enabled by Dual Working Mechanism

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Ternary strategies enhance photovoltaic device performance through integration and adaptability.
• All-polymer solar cells (all-PSCs) offer potential for flexible and lightweight energy solutions.

Purpose of the Study:

• To synthesize a novel wideband gap polymer donor, PBB2-Hs, as a guest component to optimize all-PSCs.
• To investigate the impact of PBB2-Hs on energy transfer, charge mobility, morphology, and stability of all-PSCs.

Main Methods:

• Synthesis of PBB2-Hs wideband gap polymer donor.
• Fabrication and characterization of ternary all-PSCs incorporating PBB2-Hs.
• Assessment of photovoltaic performance, photostability, storage stability, and mechanical flexibility.

Main Results:

• PBB2-Hs demonstrated efficient energy transfer and improved miscibility, forming an alloy-like structure with the host system.
• Ternary all-PSCs with 15 wt% PBB2-Hs achieved a champion efficiency of 17.66%.
• The optimized devices exhibited enhanced photostability (82% after 24h) and storage stability (91% after 1000h), along with a 1.6-fold increase in elongation at break for flexible applications.

Conclusions:

• The guest polymer PBB2-Hs effectively optimizes all-PSCs by improving photon capture, charge transfer, and molecular ordering.
• PBB2-Hs significantly enhances photovoltaic efficiency, photostability, and mechanical stability, demonstrating its potential for high-performance flexible solar cells.