Prof Uri Banin of the Hebrew University of Jerusalem. Image: Yoav Dudkevitch
Scientists claim to have achieved dynamic switching with nanoscale colours, which could lead to a new era of displays and communication networks.
Researchers in Israel claim to have achieved a way to switch colours using nanocrystals instantaneously, which could boost various technologies.
Coloured light has many modern-day applications such as lighting, displays and fibre communication networks. By taking colour-emitting semiconductors to the nanoscale – 100,000 times smaller than a human hair – the research team said an effect called quantum confinement is achieved.
This effect modifies the colour of light coming from these semiconductors (nanocrystals), which means light sources can be obtained across the entire visible spectrum of colours. But currently, different nanocrystals are needed for each specific colour and dynamic switching between the colours is not possible.
In a new experimental study, a team at the Hebrew University of Jerusalem claim to have overcome this issue by creating a novel molecule with two emission centres. The researchers said electric voltage was able to change the colour of each centre.
By changing the polarity of this electric field, the team was able to change the light being emitted from the “red” emission centre to the “green” emission centre. This allowed the team to switch to these two colours or create any combination of the two. The researchers also said that this colour switching was both immediate and reversable.
The researchers said this discovery could unlock a range of new possibilities, such as nanoscale optoelectronic devices with adjustable colours and tools for sensitive field sensing for biological applications and neuroscience. They also said that the ability to fine-tune colours in single photon sources could also be useful for future quantum communication technologies.
Prof Uri Banin – who led the research – said the experiment is a “big leap forward” in terms of nanomaterials for optoelectronics.
“This is an important step in our exposition of the idea of “nanocrystal chemistry” launched just a few years ago in our research group, where the nanocrystals are building blocks of artificial molecules with exciting new functionalities,” Banin said.
“Being able to switch colours so quickly and efficiently on the nanoscale as we have achieved has enormous possibilities. It could revolutionise advanced displays and create colour-switchable single photon sources.”
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