In a groundbreaking development, scientists at the City University of Hong Kong (CityUHK) have successfully created highly efficient, printable, and stable perovskite solar cells. This new type of solar cell has the potential to play a significant role in achieving carbon neutrality and promoting sustainable development. Unlike traditional solar cells, these perovskite solar cells can be produced at a rapid pace, comparable to the speed of newspaper printing, with a daily output of up to 1,000 solar panels.
One of the key advantages of these innovative perovskite solar cells is their flexibility and semi-transparency. This feature allows them to be integrated into light-absorbing glass windows, paving the way for the concept of “urban solar farms” in cities with numerous high-rise buildings. The research, led by Professor Alex Jen Kwan-yue, the Lee Shau Kee Chair Professor of Materials Science at CityUHK, has been published in the prestigious journal Nature Energy.
The research team at CityUHK has addressed the challenge of long-term stability in perovskite-organic tandem solar cells, which has been a significant hurdle for scientists for over a decade. By employing creative material science solutions, the team has developed a series of organic redox mediators to enhance the operational stability of wide-bandgap perovskites. The integrated cells have demonstrated an impressive retention of over 90% of their initial Power Conversion Efficiency (PCE) after 500 hours of continuous operation.
An exciting aspect of this research is the record-high efficiency achieved by the perovskite solar cells, with a certified efficiency of 24.27% and a demonstrated efficiency of 25.22%. Additionally, the device has exhibited good operational stability even in humid air conditions, with a relative humidity of 70-80%. Dr. Wu Shengfan, a key member of the research team, highlighted the innovative approach taken by CityUHK in utilizing redox and chemical synthesis methods to ensure the stability of perovskite solar cells.
The research results obtained by the CityUHK team are set to be translated into practical applications through the establishment of the start-up company, HKTech Solar Limited. Dr. Francis Lin, a postdoctoral student of Professor Jen, will manage the company. Perovskite photovoltaics offer unique advantages such as energy absorption under weak indoor light conditions and mechanical flexibility, enabling their integration into various scenarios, from large buildings to components of the Internet of Things.
Looking ahead, the CityUHK team plans to set up a pilot production line in Hong Kong with an annual output of 25 megawatts within the next year and a half. This ambitious initiative aims to launch products for industrial applications and engage with investors to test the viability of these innovative solar cells in real-world scenarios. CityUHK’s emphasis on critical thinking and cutting-edge research has played a crucial role in nurturing doctoral students who are well-equipped to tackle the most complex challenges in the field of renewable energy.