Researchers at Kyushu University in Japan have made a significant advancement in solar technology by developing a new material that enables solar cells to convert sunlight into energy at a rate previously deemed unattainable.

This innovative discovery involves a unique ‘spin-flip’ emitter, which has the capability to capture energy from sunlight that would typically be lost as heat. This breakthrough allows for an impressive energy conversion efficiency of 130 per cent, effectively surpassing the long-standing limitations observed in conventional solar cells.

Traditionally, each photon, or particle of light, could generate a single energy carrier known as an exciton. However, existing solar cell technologies have only been able to harvest energy from approximately one-third of the available sunlight, as higher-energy photons, such as blue light, are often lost as heat.

The research team employed a technique called singlet fission, which enables the splitting of excitons derived from higher-energy photons into two lower-energy excitons, thereby theoretically doubling the available energy.

Associate Professor Yoichi Sasaki, from the Faculty of Engineering at Kyushu University, elaborated on the strategies used to overcome this efficiency barrier: “One is to convert lower-energy infrared photons into higher-energy visible photons. The other is to use singlet fission to generate two excitons from a single exciton photon.” This dual approach highlights the innovative methods being explored to enhance solar energy conversion.

The findings of this pivotal research are documented in the Journal of the American Chemical Society under the study titled “Exploring spin-state selective harvesting pathways from singlet fission dimers to a near-infrared-emissive spin-flip emitter.” This work represents the latest advancement in a series of breakthroughs within the solar technology sector, contributing to the ongoing efforts to enhance the efficiency and cost-effectiveness of renewable energy sources.

Earlier this month, another notable achievement was reported by a research team in Switzerland, which set a new efficiency record for a novel type of solar cell using the so-called ‘miracle material’ perovskite. Through a combination of perovskite and silicon, the researchers attained efficiency levels comparable to those of satellite-grade solar panels, yet at a significantly reduced cost.

As the renewable energy sector continues to evolve, advancements such as these are crucial for promoting sustainable energy solutions and addressing the global energy challenge.