Australian researchers from Monash University and CSIRO have reported a way to improve the energy efficiency and longevity of solar integrated glass, while also allowing more natural light to pass through it. The researchers have demonstrated power conversion efficiencies of 15.5% and 4.1% for different types of prototype semi-transparent solar cells, with visible transmittance of 20.7% and 52.4% respectively.
This work builds on achievements made two years ago, when the same team created a solar window prototype that let through 10% of visible light and achieved 17% power conversion efficiency. According to the team, the upper power conversion efficiency achieved in the newer prototype is slightly lower than was achieved back in 2020 – 15.5% compared to 17% – but the pass-through of visible light is “significantly greater”, increasing their viability for real-world applications.
Also significant is the “excellent long-term stability” the caesium and formamidinium perovskite solar cells demonstrated when tested for continuous illumination and heating, to mimic the conditions the solar windows would experience in real-world use. The prototypes with that particular perovskite composition were said to maintain 85% of its initial power conversion efficiency after 1000 hours under continuous illumination.
As the expected lifetime for windows and buildings is between 25 and 40 years, the team feels that this finding is an important step forward toward realizing commercialized, next-generation solar window technologies.
“This work provides a major step forward towards realizing high efficiency and stable perovskite devices that can be deployed as solar windows to fulfil what is a largely untapped market opportunity,” said project leader, Professor Jacek Jasieniak from the Department of Materials Science & Engineering at Monash.
