NUS Sets Record With 26.4% Perovskite-Organic Solar Cell

• NUS researchers achieve record 26.4% efficiency in flexible perovskite–organic tandem solar cell, paving the way for smart wearable applications.

Researchers at the National University of Singapore (NUS) have set a new benchmark in solar technology, reporting a certified world-record efficiency of 26.4% for a perovskite–organic tandem solar cell. The innovation, developed by a team led by Assistant Professor Hou Yi at the College of Design and Engineering, showcases a major leap in thin-film solar cell design.

The record-setting device is built on a 1 cm² active area and outperforms all previous devices of its kind. The core advancement stems from a newly engineered narrow-bandgap organic absorber that dramatically enhances the capture of near-infrared (NIR) photons — a known limitation in tandem solar cell efficiency.

“Perovskite–organic tandem solar cells offer lightweight, flexible power solutions ideal for drones, smart fabrics, and wearable electronics,” said Prof Hou, who also leads the Perovskite-based Multijunction Solar Cells Group at SERIS, NUS’s Solar Energy Research Institute.

To overcome poor NIR absorption, the team designed an asymmetric organic acceptor with extended molecular conjugation. This not only pushed absorption deeper into the NIR spectrum but also preserved strong charge separation and optimized molecular packing.

Ultrafast spectroscopy and device physics confirmed efficient charge collection with minimal energy loss. The final cell structure pairs the organic subcell with a high-performance perovskite top layer, joined by a transparent conducting oxide (TCO) interconnector.

While the team achieved up to 27.5% efficiency on smaller 0.05 cm² samples, the 26.4% efficiency on 1 cm² cells was independently certified, making it the highest officially reported result among perovskite-organic and similar tandem devices.

Looking ahead, Prof Hou’s group aims to improve long-term operational stability and move toward pilot-line manufacturing, paving the way for scalable, flexible solar films. These could one day be used in self-powered health patches, textiles with biometric sensors, or AI-driven devices needing lightweight, integrated power sources.