
AsianScientist (Oct. 19, 2018) – A research group consisting of scientists in Japan and the Netherlands has discovered perovskite crystals that convert light to energy more efficiently. Their findings are published in the journal Nature Communications.
Perovskites are a group of crystals that have many promising properties for applications in nanotechnology. However, one useful property that was thus far unobserved in perovskites is carrier multiplication—an effect that makes materials much more efficient in converting light into electricity.
In the present study, scientists at the University of Amsterdam (UA), Netherlands, and Osaka University (OU), Japan demonstrated that certain perovskites do in fact exhibit carrier multiplication. The team was led by Professor Tom Gregorkiewicz of UA and Professor Yasufumi Fujiwara of OU.
When a single particle of light—a photon—falls on the surface of a typical solar cell, it excites a single electron, creating a corresponding ‘hole’ where the electron used to be, and this results in an electrical current. If the infalling light is energetic enough, further electron-hole pairs can be excited, resulting in carrier multiplication. The researchers observed this happening in perovskite nanocrystals made out of cesium, lead and iodine. They claimed that the carrier multiplication effect in their nanocrystals is higher than that of any other material reported thus far.
“Until now, carrier multiplication had not been reported for perovskites. That we have now found it is of great fundamental impact on this upcoming material. For example, this shows that perovskites can be used to construct very efficient photodetectors, and in the future, perhaps solar cells,” said Dr. Chris de Weerd of UA who successfully defended her PhD thesis with the findings.
The article can be found at: De Weerd et al. (2018) Efficient Carrier Multiplication in CsPbI3 Perovskite Nanocrystals.
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Source: Osaka University; Photo: Pexels.
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