Crown ethers improve perovskite solar cell security

• EPFL researchers have actually utilized an unmatched method with multimodal host-guest complexation to considerably improve the security of perovskite solar cells while additionally decreasing the launch of lead into the setting

Perovskites are hybrid compounds made from metal halides and also organic constituents, as well as show wonderful potential in a variety of applications, e.g. LED lights, lasers, as well as photodetectors. Their major contribution remains in solar cells, where they are positioned to surpass the market and replace their silicon equivalents.

Among the leading candidates for very reliable and steady solar cells are formamidinium lead iodide perovskites, which show excellent light-harvesting capabilities. Nevertheless, their security is still a problem, specifically under environmental and also operating problems, which restrict their optoelectronic application.

Now, a joint group of researchers led by Professor Michael Grätzel at EPFL's School of Basic Sciences have resolved the difficulty by developing a "a multimodal host-- visitor complexation approach." Released in Nature Communications, the technique involves making use of a participant of the crown ethers, a family members of cyclic substances whose ring-like atomic framework looks like a crown.

The researchers made use of the dibenzo-21-crown-7 in the construction of formamidinium lead iodide perovskite solar cells. They showed the performance of this synergistic method with cesium steel ions, for which the crown ether shows a strong affinity. Acting as an automobile, the crown ether assembles at the perovskite film's user interface as well as delivers the cesium ions into its inside.

"We utilize this multimodal host-- guest-complexation to regulate the surface area of the perovskite films as well as their bulk make-up at the same time," clarifies Dr. Jovana V. Milić, who was associated with the research.

"It is additionally really exciting to see that photoactive formamidinium lead iodide perovskite can be supported in moist ecological conditions for more than one year," claims EPFL researcher Dr. Hong Zhang, the initial writer of the research study.

The overall impact is a substantially boosted security of the perovskite solar cells, revealing power-conversion efficiency over 24% and a boosted operational stability, keeping more than 95% of their efficiency for 500 h under continual procedure. As an added benefit, the crown ether also aids bind lead ions, decreasing their release right into the setting.