Monash's high-performance, colour-neutral solar cells for windows

Amit Kessel and a collaborative team from Monash and UNSW have demonstrated semi-opaque perovskite solar cells (SO-PSCs) that combine high efficiency, excellent colour-neutrality, and the clarity required for real building windows.

In 2025, researchers at Monash University and UNSW, supported by the Australian Centre for Advanced Photovoltaics (ACAP), achieved a major step forward in the development of next-generation photovoltaic windows. Led by Professor Jacek Jasieniak, the team demonstrated semi-opaque perovskite solar cells (SO-PSCs) that combine high efficiency, excellent colour-neutrality, and the clarity required for real building windows – addressing one of the most important challenges in integrating solar generation into city architecture.

“This work has the potential to significantly support decarbonisation of dense urban areas,” says Professor Jacek Jasieniak. 

Traditional rooftop solar alone cannot deliver meaningful on-site energy offsets for modern high-rise buildings which rely heavily on glass façades. Solar-harvesting windows offer a compelling solution – but only if they can maintain natural light, avoid visible tinting and haziness, and still generate significant power. 

The team’s breakthrough was to use a rapid, scalable self-assembly process that forms precise microscopic patterns in the perovskite layer, allowing light to pass through while the active areas generate electricity. This “bottom-up” patterning approach avoids harsh fabrication steps that can damage delicate perovskite materials.

Semi-opaque perovskite solar windows. Adjusting the surface coverage of the cells controls how much light enters the room and how much is converted into electricity.

“A critical challenge that all novel technologies face is the transition from ‘lab to fab’. We focused on developing a low-cost manufacturing method that can be easily scaled up, reducing future barriers to market entry,” explains Amit Kessel, Phd student and lead author of the paper published in ACS Energy Letters, “Semi-Opaque Perovskite Solar Cells for Color-Neutral Photovoltaic Windows”.^[1]

The resulting devices achieved the highest reported efficiencies for colour-neutral perovskite solar cells in the 20–50% transparency range – comparable to industry-leading semi-transparent technologies, but with superior visual quality and a natural, untinted appearance. 

Importantly, this work benefited from advanced device analysis undertaken in collaboration with Professor Ziv Hameiri’s team at UNSW, including photoluminescence imaging to diagnose voltage loss pathways and guide further optimisation.

“As cities move towards net-zero design, every part of a building must work harder,” said Professor Jasieniak.

“Our technology shows that windows can become clean energy generators without compromising the way buildings look or feel.” 

This research is building the foundation for future large-area solar window manufacturing. The building integrated market is considered niche when compared to the global PV sector but, Professor Jasieniak says, “A new market entry point for perovskite solar cells – in which it does not compete with silicon – will drive development of this emerging material.” 

Reference

^[1] Amit Kessel, Juan F. Benitez-Rodriguez, Shuai Nie, Ziv Hameiri, and Jacek J. Jasieniak, “Semi-Opaque Perovskite Solar Cells for Color-Neutral Photovoltaic Windows”, ACS Energy Letters October 7,2025 10 (11), 5314-5321, DOI: 10.1021/acsenergylett.5c02792