Groundbreaking Solar Energy Development in Hong Kong

Researchers from The Hong Kong Polytechnic University (PolyU) have made waves in the renewable energy sector, achieving an unprecedented power-conversion efficiency (PCE) of 33.89% with their innovative perovskite/silicon tandem solar cells. This remarkable feat, in collaboration with an energy tech firm and Soochow University, paves the way for a new era in high-efficiency solar technology.

Tackling Longstanding Challenges in Photovoltaics

While tandem solar cells have proven to be more efficient than traditional single-junction designs, challenges with energy loss and charge extraction at the device interface have hindered their widespread use. A significant obstacle has been the interfacial recombination at the perovskite/electron transport layer, which previously restricted further efficiency improvements.

Innovative Solution: Bilayer Interface Passivation

To overcome these barriers, the PolyU researchers implemented a groundbreaking bilayer interface passivation strategy. This approach integrates a super-thin lithium fluoride (LiF) layer with an ethylenediammonium diiodide (EDAI) molecule, effectively combining field-effect and chemical passivation. This dual-layer passivation not only minimizes non-radiative recombination but also bolsters device stability and longevity.

A Design Optimized for Maximum Efficiency

The advanced passivation technique was applied to a double-textured silicon heterojunction cell designed for optimal light absorption and charge transport. The structure features a mildly textured front surface to capture maximum light and a heavily textured rear surface to ensure robust passivation—resulting in a tandem solar cell that generates superior photocurrent while maintaining stellar electrical performance.

Setting New Standards in Solar Efficiency

The groundbreaking device achieved an independently verified PCE of 33.89%, eclipsing the Shockley-Queisser limit of 33.7% for single-junction cells. This certification marks a pivotal moment, signifying the first time a two-junction solar cell has officially surpassed this efficiency threshold. Alongside its high conversion efficiency, the device boasts a fill factor of 83% and an impressive open-circuit voltage of nearly 1.97 volts—clear indicators of its advanced performance.

Sustainability Meets High Efficiency

Beyond just peak performance, this innovative technology also emphasizes durability, a vital trait for commercial success. The materials and strategic design ensure that the cell can maintain its high efficiency over time, addressing the pressing need for sustainable energy solutions in a world increasingly reliant on renewable sources.

A New Era in Photovoltaic Performance

This breakthrough underscores the potential of interface engineering and material innovation. By merging advanced perovskite materials with established silicon technologies, the research team has crafted a hybrid solar solution that harnesses the best qualities of both. With perovskites providing exceptional light absorption and silicon serving as a stable commercial platform, this tandem structure represents a viable pathway for the future of solar technology.

Looking to the Future of Renewable Energy

The implications of this research extend far beyond efficiency records. As global energy demands rise, such innovations play a crucial role in transitioning society toward low-carbon, sustainable energy systems. The PolyU team’s success not only touches upon record-breaking efficiencies but also heralds new avenues for research in perovskite-based photovoltaics, setting a strong foundation for future advancements in renewable energy technology.

As the team continues to explore the optoelectronic properties of advanced perovskite materials and their application in new photovoltaic architectures, the future of solar energy looks brighter than ever.