UNSW team sets large-scale perovskite efficiency record
Engineers from UNSW Sydney have collaborated with energy company UtmoLight to set a benchmark for 676cm2 perovskite solar submodules.
The UNSW team, led by Xiaojing Hao, achieved a certified stabilised power conversion efficiency of 23.5 percent, beating the previous benchmark by 0.6 percentage points.
The result is 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 around 1cm2.
The researchers say the world record demonstrates that perovskite solar technology can maintain high efficiency across much larger areas than laboratory-scale cells, highlighting its potential for scalable manufacturing and widespread use in photovoltaic modules.
“For us, this is not only about setting another efficiency record. It is about developing materials and device concepts that continue to perform when they are translated from laboratory cells to industrially relevant areas,” said Hao, from UNSW’s School of Photovoltaic and Renewable Energy Engineering.
“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.”
Perovskite is not yet ideal for widespread PV use because it can degrade when exposed to moisture, heat and prolonged sunlight. In addition, larger perovskite modules require precise control over film uniformity, crystallisation, defects, interfaces and electrical interconnection across a substantially greater area – which means scaling them up from small lab samples can be problematic.
In a further breakthrough, the UNSW-UtmoLight partnership achieved the world record result in combination with 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.
However, nickel oxide can also adversely react with the perovskite material, adding to instability and adding another manufacturing step to the device.
The UNSW team, which included Zhen Li, and Ziyue Feng, 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,” Hao says.
“UtmoLight’s expertise in large-area processing and module fabrication has been essential in translating our materials and device concepts into a high-performance submodule.”
The researchers now hope to be able to scale up the efficiency testing even more in the next few months 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 around 18-19 percent efficiency for that larger solar module, but acknowledge that further work is needed to improve efficiency, reproducibility and long-term stability before the technology can be widely deployed.
Hao was recently awarded $6.3m, opens in a new window by the Australian Renewable Energy Agency (ARENA) to help continue her work to make perovskite-silicon solar panels more efficient and reliable.
