Perovskite materials have the potential to take the place of silicon in solar panel technology because they are easier to make and more effective at absorbing higher energy forms of light. Sadly, researchers are still working to improve the stability and durability of these perovskites.
In a recent study, researchers were able to considerably raise the performance of a specific kind of this substance called a lead-halide perovskite. Light conversion efficiency was boosted by 250 percent by mixing the perovskite with a metal substrate as opposed to glass.
Professor of optics at the University of Rochester in New York Chunlei Guo claims that "no one else has got to this observation in perovskites."
"The interaction of the electrons within a perovskite is completely altered when a metal platform is placed beneath it. Hence, we engineer that interaction using a physical technique."
Although there is still more to be done before this technology can be applied to solar panels, this is another another sign that perovskite crystalline structures may soon replace other materials as the preferred means of increasing solar power output.
Solar panels generate an electrical current by using photons from sunshine to excite electrons into moving away from their position near to an atom. The energy that could have been converted into electricity, however, is wasted as heat when electrons and the gaps they have left behind recombine.
The researchers discovered that they could decrease such recombination and boost efficiency by including a metal substrate. The group also demonstrated how increasing efficiency rates might be achieved by using a substrate for the light-absorbing perovskite that alternated between layers of metal and dielectric (insulating) material.
The photons' produced configurations of electrons and their holes are reversed by the metal substrate, which functions as a mirror image. Efficiency is increased through "a lot of interesting physics." It serves as an illustration of how advancements in solar cell technology don't always have to concern the absorbing substance itself.
In a wet lab, a piece of metal may accomplish just as much as sophisticated chemical engineering, claims Guo.
The main obstacle to the widespread use of perovskites, despite the fact that their effectiveness is constantly increasing, is their short lifespan. It might end up being the best course of action to combine it with silicon inside solar panels.
This method of combining metals with perovskites is expected to continue to advance, according to the study's authors, allowing us more control over solar panels' ability to convert light into power.
The fact that there are many different metals and halides that can be used to make perovskites is one of its appeals, and the efficiency-boosting method described here should work in all cases. That may be particularly crucial as scientists hunt for alternatives to lead-halides, which, while currently outperforming other composite materials, are known to have negative effects on the environment.
"We may then utilize our physics-based strategy to further improve their performance as new perovskites arise," explains Guo.