Stunning solar cells offer 25% efficiency, 95% stability after 2,000 hrs of trial

Researchers have developed a new fabrication technique for substantially enhancing the prospects of commercializing perovskite solar cells.

Developed by researchers at the City University of Hong Kong (CityUHK), the technique improves stability, reliability, efficiency and affordability of perovskite solar cells.

Using the technique, the CityUHK team has built a simple device structure that can facilitate future industrial production and enhance confidence in the commercialization of perovskite solar cells.

Significant step in making solar energy more accessible

They improved the long-term stability of perovskite solar cells with an atomic-layer deposition (ALD) method. The layer replaces the fullerene electron transport layer with tin oxide.

Professor Zhu Zonglong of the Department of Chemistry stated that the mineral perovskite is used extensively to convert sunlight into electricity efficiently.

Zonglong underlined that the improvements in stability and the simplification of the production process of perovskite solar cells represent a significant step forward in making solar energy more accessible and affordable.

In broad terms, the CityUHK team is working on a new type of solar cell that can turn sunlight into electricity more efficiently and last longer than current solar cells, according to a press release .

Operational stability

Two innovations have been developed by the team for creating the structure of solar cells .

The first innovation is the integration of the hole-selective materials and the perovskite layers, which simplifies the manufacturing process. The second is that the operational stability of the device is greatly enhanced by using the inorganic electron transport layer, tin oxide, which has excellent thermal stability, to replace traditional organic materials such as fullerene and BCP, according to researchers .

Dr Gao Danpeng, co-author of the Science paper and a post-doc at CityUHK, stated that the device structure reported in this study represents the most simplified architecture in the current field of perovskite solar cells, offering significant advantages for industrialisation.

This solution does not require a traditional organic transfer layer, effectively reducing the material cost in the manufacturing process while greatly simplifying the production steps, according to Dr Gao.

Power conversion efficiencies exceeding 25%

Professor Zhu claimed that the team has achieved power conversion efficiencies exceeding 25% by optimising oxygen vacancy defects within the tin oxide layer while retaining over 95% efficiency after 2,000 hours of continuous operation under rigorous test conditions.

Researchers maintained that this performance exceeds the stability of traditional perovskite solar cells, meeting several industry benchmarks for longevity. The results pave the way for more reliable and efficient solar cells, simplifying manufacturing processes and making producing solar cells at scale more cost-effective, according to the study.

Professor Zhu claimed that the research has the potential to be implemented in solar energy systems within the next 5 years.

“This research is a critical step towards achieving more sustainable and environmentally friendly energy production globally,” added Zhu.

The study titled “Long-term stability in perovskite solar cells through atomic layer deposition of tin oxide” is published in Science .