Scientists from the National University of Singapore have announced a record 27.1% energy conversion efficiency from a novel triple-junction solar cell they developed. The breakthrough, published in the journal Nature, claims to overcome the limitations in current solar cell technologies.

Solar cells work by absorbing energy from sunlight and converting it into electricity. Multi-junction cells layer different materials that absorb different ranges of solar energy, increasing the overall efficiency. However, most existing multi-junction designs suffer from energy losses and instability issues.

The researchers engineered a new type of perovskite solar cell by incorporating cyanate, a unique molecule, into its structure. Perovskites can be solution-processed and essentially painted or printed onto surfaces like flexible plastic, paper, or glass, making them versatile and easy to transport.

“Remarkably, after 15 years of ongoing research in the field of perovskite-based solar cells, this work constitutes the first experimental evidence for the inclusion of cyanate into perovskites to boost the stability of its structure and improve power conversion efficiency,” said one of the researchers, Assistant Professor Hou Yi.

The cyanate-perovskite cell worked at over 96% capacity after 300 hours of maximum power operation, demonstrating its durability. The solar cell also achieved a higher voltage of 1.422 volts compared to 1.357 volts for conventional perovskite solar cells, with a significant reduction in energy loss.

It was then integrated with a silicon solar cell to create a triple-junction tandem device. Triple-junction designs can theoretically exceed 50% efficiency by capturing more of the solar spectrum. However, achieving this has been challenging with conventional materials.

This triple-junction cell is the most efficient of its kind ever certified, the scientists claimed.

“Collectively, these advancements offer ground-breaking insights into mitigating energy loss in perovskite solar cells and set a new course for the further development of perovskite-based triple junction solar technology,” added Hou.

The researchers plan to scale up the technology to full-size solar panels and modules while maintaining record-setting efficiency. The next steps include optimizing the interfaces between cell layers and further tweaking the perovskite composition.

Just last month, UK-based solar cell manufacturing company Oxford PV, in collaboration with the Fraunhofer Institute for Solar Energy Systems, reported a 25% conversion efficiency for its perovskite solar modules.

Meanwhile, scientists at the Massachusetts Institute of Technology have found a way to restructure perovskite cell surfaces to reduce defects using nanoscale engineering.