UNSW researchers achieve 23.5% efficiency record for large-scale perovskite PV submodule

Engineers from the University of New South Wales Sydney (UNSW) have teamed with Chinese perovskite module producer UtmoLight to establish a world efficiency record for large-scale perovskite solar submodules.

The UNSW team, led by Scientia Professor Xiaojing Hao from UNSW’s School of Photovoltaic and Renewable Energy Engineering, achieved a certified stabilised power conversion efficiency of 23.5% for a perovskite submodule, beating the previous benchmark by 0.6 percentage points.

The researchers said the result is particularly significant because it sets an efficiency benchmark for a 30 x 30cm perovskite submodule, with an aperture area of 676cm2, further narrowing the efficiency gap with small-area laboratory cells, which are typically only about 1cm2.

Hao said the milestone demonstrates that perovskite solar technology can maintain high efficiency across much larger areas than laboratory-scale cells, reinforcing its potential for scalable manufacturing and widespread use in PV modules.   

“For us, this is not only about setting another efficiency record,” she said. “It is about developing materials and device concepts that continue to perform when they are translated from laboratory cells to industrially relevant areas.”

“Materials that work exceptionally well in a small laboratory device do not necessarily behave in the same way under scaled-up processing conditions.”

“Our focus is therefore not simply on finding high-performance materials, but on understanding how to design materials and interfaces that remain effective under the conditions required for large-area fabrication.”

The world record result was achieved following the removal of the conventional layer of nickel oxide which is commonly used in perovskite solar cells, and particularly in sub-module size, to help prevent electrical short circuits and ensure the device functions properly. Nickel oxide can however adversely react with the perovskite material, adding to instability and adding another manufacturing step to the device.

Hao said the UNSW team used materials innovation, and a different approach to fabricating the solar cell, to eliminate the need for the nickel oxide layer, while also enabling a hole-selective contact to form directly during fabrication rather than through a conventional layer-by-layer process.

“Achieving high efficiency at this scale requires much more than simply transferring a laboratory process to a larger substrate,” she said.

The researchers now hope to be able to scale up the efficiency testing by producing a full-scale module with a 2.8m2 area, representative of full-scale commercial PV module dimensions, to further validate their work.

They hope to achieve about 18-19% efficiency for that larger solar module, but acknowledge further work is needed to improve efficiency, reproducibility and long-term stability before the technology can be widely deployed.

The work is part of UNSW’s industry partnership with UtmoLight, announced earlier this year.

The agreement enables the partners to conduct collaborative research on perovskite technologies and jointly promote the industrialisation of perovskite PV technologies. It also allows the researchers to test the scalability of ideas at the very start of the process, rather than spending years innovating materials that may not work at industrial scale.

Hoa said this is particularly important for future perovskite technologies, where the transition from laboratory research to large-scale manufacturing remains a key challenge.

“We have been able to test our ideas to check if they can be upscaled, which means that we are not wasting our time on things that aren’t feasible,” she said, adding that “this is also good for industry as well, because they get to know whether there are innovations that can help them overcome some limitations in their large-scale processing systems.”