Chinese Researchers Achieve Record 19.1% Efficiency in Ultra Stable Flexible Polymer Solar Cells

Wuhan University researchers unveil a flexible polymer solar cell reaching 19.1% efficiency with record-breaking 2,000-hour stability in ambient air.

By: AXL Media

Published: Feb 28, 2026, 3:35 AM EST

Source: The information in this article was sourced from Interesting Engineering

A Breakthrough in Organic Photovoltaic Performance

A research team based in China has successfully demonstrated a new iteration of polymer solar cells (PSCs) that reach a power conversion efficiency of 19.1%, marking a significant step toward the commercialization of flexible energy technology. These devices, developed at the Wuhan University of Technology, address the historical trade-off between high energy output and long-term durability. By focusing on the underlying molecular mechanisms that typically cause organic materials to degrade, the researchers have produced a cell capable of sustained operation in ambient conditions, which has previously been a major hurdle for this specific branch of solar technology.

Addressing the Structural Weakness of Polymeric Acceptors

The study, recently detailed in the journal Matter, identifies specific vulnerabilities in the chemical bonds of current solar materials that lead to rapid degradation. According to the research findings, the polymer acceptor known as PY-IT contains extra weak bonds between its repeating units, which contributes to inferior stability when compared to other solar technologies. To combat this, the team investigated the structural and morphological changes that occur during thermal stress and light exposure, seeking a way to reinforce the material at a molecular level without sacrificing its ability to conduct electricity.

Small Molecule Integration as a Stability Catalyst

To overcome these inherent chemical weaknesses, the researchers introduced a strategy involving the blending of small-molecule acceptors into the existing polymeric matrices. This method functions by disentangling complex polymer chains and promoting a more ordered molecular packing structure. By reducing the "free volume" within the photoactive layer, the team effectively created more efficient pathways for charge transport. This structural refinement not only boosts the efficiency of the energy conversion but also provides a robust defense against the environmental factors that typically cause organic solar cells to fail.