Researchers uncover one other strategy to sequester lead in perovskite solar cells

Scientists on the National Renewable Energy Laboratory (NREL) and Northern Illinois University (NIU) have efficiently prevented lead from escaping broken perovskite solar cells. The analysis effort is their newest work in addressing issues about potential lead toxicity.

The light-absorbing layer in perovskite solar cells accommodates a small quantity of lead. Simply encapsulating solar cells doesn’t cease lead from leaking if the gadget have been to grow to be broken by extreme climate circumstances, similar to a hailstorm. Instead, chemical absorption holds the important thing.

The researchers report with the ability to seize greater than 99.9% of leakage. Their findings, in an article titled “On-device lead absorbing tapes for sustainable perovskite solar cells,” seems within the journal Nature Sustainability.

The authors are Fei Zhang, Jinhui Tong, and Kai Zhu of NREL; and Xun Li, Jianxin Wang, and Tao Xu of NIU.

“It is valuable to develop an approach that can be applied to various perovskite solar cell configurations,” Zhu stated.

Zhu and a few of the similar researchers in 2020 reported profitable experiments in sequestering lead ought to a perovskite cell grow to be broken. They developed lead-absorbing movies, utilized them to the 2 sides of a cell, after which smashed them with a hammer and slashed them with a knife. The broken cell was then immersed in water. The scientists discovered the movies prevented greater than 96% of the lead from leaking into the water.

Researchers elsewhere adopted up on the lead concern and developed a resin that may very well be included right into a perovskite solar cell. But, because the NREL and NIU scientists famous, “These additional modifications could complicate the device fabrication and configuration and potentially limit device performance and scale-up.”

Instead, the authors famous within the paper, a greater proposition is to develop sturdy and extremely environment friendly lead-absorbing elements that may be “conveniently mounted” onto the perovskite solar cell as an adjunct.

The NREL and NIU scientists imagine they’ve discovered an answer in utilizing a tape-like chemical absorption method that may be readily put in on each side of a perovskite solar cell. In a sequence of exams, the tapes captured nearly the entire lead leakage with out compromising the cell’s efficiency and operation. The tapes have been fabricated from a normal solar ethylene vinyl acetate (EVA) movie and a pre-laminated di(2-ethylhexyl) methanediphosphonic acid layer.

After damaging the perovskite solar cells, the scientists performed a sequence of exams to quantify how a lot lead would escape into water. In one experiment, the focus of lead in water that fell on the broken gadget averaged about 19.14 elements per million. The tape introduced that determine all the way down to 2.13 elements per billion. To put this determine in context, the Environmental Protection Agency considers water secure to drink if the lead content material is lower than 15 elements per billion.

“Since EVA has been extensively used as a cost-effective and durable encapsulating material for silicon-based solar panels, the integration of lead-absorbing materials with EVA provides an industrially ready and stand-alone component to facilitate the future market adoption of perovskite solar cells,” Xu stated.