NUS scientists record 24.35% PCE for perovskite solar cells

A team of scientists from the National University of Singapore (NUS) have designed perovskite solar cells that have achieved an efficiency of 24.35% with an active area of 1 cm². This achievement could pave the way for cheaper, more efficient and durable solar cells.

To facilitate consistent comparisons and benchmarking of different solar cell technologies, the photovoltaic (PV) community uses a standard size of at least 1 cm² to report the efficiency of 1 sun solar cells in the “Solar Cell Efficiency Tables”. Prior to the achievement by the NUS team, the best 1 cm² perovskite solar cell recorded a power conversion efficiency of 23.7%.

Perovskites are a class of materials that exhibit high light absorption efficiency and ease of fabrication, making them promising for solar cell applications. In the past decade, perovskite solar cell technology has achieved several breakthroughs and the technology continues to evolve. Assistant Professor Hou Yi, leader of the NUS research team, said that the scientists undertook a dedicated effort to develop innovative and scalable technologies aimed at improving the efficiency of 1 cm² perovskite solar cells.

“Our objective was to bridge the efficiency gap and unlock the full potential of larger-sized devices. Building on more than 14 years of perovskite solar cell development, this work represents the first instance of an inverted-structure perovskite solar cell exceeding the normal structured perovskite solar cells with an active area of 1 cm², and this is mainly attributed to the innovative charge transporting material incorporated in our perovskite solar cells. Since inverted-structure perovskite solar cells always offer excellent stability and scalability, achieving a higher efficiency than for normal-structured perovskite cells represents a significant milestone in commercialising this cutting-edge technology,” Hou said.

This achievement was made by successful incorporating a novel interface material into perovskite solar cells. Team member Dr Li Jia said that the introduction of this novel interface material brings forth a range of advantageous attributes, including excellent optical, electrical, and chemical properties. “These properties work synergistically to enhance both the efficiency and longevity of perovskite solar cells, paving the way for significant improvements in their performance and durability,” Li said.

The results reported by the NUS team mark a milestone in advancing the commercialisation of a low-cost, efficient, stable perovskite solar cell technology. Building upon this development, Hou and his team aim to push the boundaries of perovskite solar cell technology even further. Another key area of focus is to improve the stability of perovskite solar cells, as perovskite materials are sensitive to moisture and can degrade over time. Hou said that the researchers are developing a customised accelerating aging methodology to bring this technology from the lab to fabrication. Their next goal is to deliver perovskite solar cells with 25 years of operational stability.

The researchers are also working to scale up the solar cells to modules by expanding the dimensions of the perovskite solar cells and demonstrating their viability and effectiveness on a larger scale. “The insights gained from our current study will serve as a roadmap for developing stable, and eventually, commercially viable perovskite solar cell products that can serve as sustainable energy solutions to help reduce our reliance on fossil fuels,” Hou said.

The research findings were published in the scientific journal Progress in Photovoltaics.

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