Researchers from Northern Illinois University and the National Renewable Energy Laboratory (NREL) of the United States Department of Energy (DOE) in Golden, Colorado, have reported a potential breakthrough that could speed the commercialization of highly promising perovskite solar cells (PSCs) for use in solar panels.
The scientists explain the invention of a cost-effective Scotch-tape-like film that can be put to PSCs and collect 99.9% of spilled lead in the event of solar cell breakdown in a brief communication published in the journal Nature Sustainability on October 28, 2021.
According to the study team, the industry-ready film would help address health and safety issues without impairing perovskite solar-cell efficiency or operation. The lead-absorbing film was put to the test by submerging injured cells in water.
“Our practical approach mitigates the potential lead-leakage to a level safer than the standard for drinking water,” said NIU Chemistry Professor Tao Xu, who co-led the research with Kai Zhu of NREL’s National Renewable Energy Laboratory.
“We can easily apply our lead-absorbing materials to off-the-shelf films currently used to encapsulate silicon-based solar cells at the end of their production, so existing fabrication processes for PSCs would not be disrupted,” Xu added. “At the end of PSC production, the films would be laminated to the solar cell.”
PSCs are a new type of solar cell that has a high power conversion efficiency (over 25.5 percent) and low production costs, making them a rising star in the field of solar energy.
Perovskite solar cells hold great hope for a more sustainable future. This research provides a practical and industry-ready strategy for reducing potential lead leakage from lead-containing PSCs, paving the way for future perovskite-based solar technology commercialization.
Tao Xu
However, due of fundamental obstacles, such as potential lead toxicity, PSCs are not yet commercially viable on a large scale.
Small amounts of water-soluble lead are still required in the light-absorbing layer of high-efficiency PSCs, which must be able to survive harsh weather in order to be commercially viable.
Significant lead leakage from damaged cells would be hazardous to one’s health. The transparent tapes use lead absorbents constructed from a normal solar ethylene vinyl acetate (EVA) film and a pre-laminated layer of lead-absorbing material to address these concerns.
As in the usual encapsulation procedure used in silicon-based sun cells, the tape can be applied to both sides of produced PSCs. The scientists exposed the film-encapsulated PSCs to outdoor, rooftop settings for three months as part of their evaluation of the new technology’s durability.
The solar cells were then damaged with razor blades and hammers before being submerged in water for seven days. The lead-absorbing tapes were found to have lead-sequestration effectiveness of more than 99.9%.
“Perovskite solar cells hold great hope for a more sustainable future,” Xu said. “This research provides a practical and industry-ready strategy for reducing potential lead leakage from lead-containing PSCs, paving the way for future perovskite-based solar technology commercialization.”
The Solar Energy Technology Office of the DOE’s Office of Energy Efficiency and Renewable Energy funded the study. Authors on the Nature Sustainability communication include NIU Ph.D. students Xun Li and Jianxin Wang, as well as NREL Chemistry and Nanoscience Center postdoctoral researchers Fei Zhang and Jinhui Tong.
