New Generation Solar Cells Pass Strict Testing Standards for Heat and Humidity

A team of research scientists led by the University of New South Wales, in collaboration with the University of Sydney, have, for the first time, produced a new generation of experimental solar energy cells that have passed the International Electrotechnical Commission (IEC) testing standards for heat and humidity.

These tests help to determine if solar cell modules can withstand the effects of outdoor operating conditions by exposing them to repeated temperature cycling between -40 degrees Celsius and 85 degrees Celsius, as well as an exposure to 85% relative humidity.

According to the press statement, the perovskite solar cells survived more than 1,800 hours of the IEC ‘damp heat’ test and 75 cycles of ‘humidity freeze’ test, exceeding the requirement of the set standard for the first time.

Solar energy systems are now widespread in both industry and domestic housing. Most current systems rely on silicon to convert sunlight into useful energy.

Scientists have been exploring new materials that can be stacked on top of silicon to improve the rate of energy conversion.

The release states that one of the most promising materials so far has been the metal halide perovskite, “which may even outperform silicon on its own.”

“Perovskites were a really promising prospect for solar energy systems,” said Professor Anita Ho-Baillie, the inaugural John Hooke Chair of Nanoscience at the University of Sydney.

“They are very inexpensive, 500 times thinner than silicon and are therefore flexible and ultra-lightweight. They also have tremendous energy enabling properties and high solar conversion rates,” she stated.

According to the release, under continual exposure to the sun and other elements, solar panels experience extremes of heat and humidity. Experiments have shown that under such stress, unprotected perovskite cells become unstable, releasing gas from within their structures.

“Perovskite cells will need to stack up against the current commercial standards. That is what is so exciting about our research. We have shown that we can drastically improve their thermal stability,” Ho-Baillie said.

The scientists did this by suppressing the decomposition of the perovskite cells using a simple, low-cost polymer-glass blanket.

The lead author Dr. Lei Shi conducted the experimental work Professor Ho-Baillie’s research group in the School of Photovoltaic and Renewable Energy Engineering at the University of New South Wales.

“Understanding this process, called ‘outgassing,’ is a central part of our work to develop this technology and to improve its durability,” said Ho-Baillie.

On an experimental basis, the past ten years are said to have seen the performance of perovskites cells improve from low levels to being able to convert 25.2% of energy from the sun into electricity, which is comparable to silicon-cell conversion rates that took 40 years to achieve.

Further, the release states that for the first time, the research team used gas chromatography-mass spectrometry (GC-MS) to identify the signature volatile products and decomposition pathways of the thermally stressed hybrid perovskites commonly used in high-performance cells. Using this method, they found that a low-cost polymer-glass stack with a pressure-tight seal was effective in suppressing the perovskite ‘outgassing,’ the process that leads to its decomposition.

“We expect this work will contribute to advance for stabilizing perovskite solar cells, increasing their commercialization prospects,” Ho-Baillie said.

Recently, Mercom reported that Australian scientists published a research paper that stated that they have succeeded in producing semi-transparent perovskite solar cells that can generate electricity.

In September 2019, scientists from the Australian National University (ANU), had a breakthrough in the efficiency of solar cells, an outcome multiple entities around the world are incessantly attempting to achieve.

Image credit: University of New South Wales