Researchers at ETH Zurich have used perovskite materials to create ultra-pure green light for new light-emitting diodes that may pave the way for visibly improved color quality in TVs and smartphones. "To date, no one has succeeded in producing green light as pure as we have," says the ETH Zurich team.

The team explains that it is basically already possible to achieve efficient-enough red and blue light, while green light still needs to improve. This is, the team says, due mainly to human perception, since the eye is able to distinguish between more intermediary green hues than red or blue ones. "This makes the technical production of ultra-pure green very complex, which creates challenges for us when it comes to developing technology and materials," says co-lead author of the report.

A team of researchers from Cambridge, MIT, Oxford, Bath and Delft universities is working on perovskite-based "solar tarp" that can be rolled onto a rooftop, instead of using rigid and heavy panels. This could, on top of other advantages, significantly bring down installation costs.

The team explains that the idea of using perovskites isn’t new, but the problem had been that tiny imperfections in the mineral’s crystal structure would trap electrons before their energy could be tapped. The team successfully tested a treatment that uses the right combination of light and humidity during the manufacturing process to “fix” the material, getting it ready for potentially years of trouble-free, ultra-efficient use.

Fuji Pigment recently reported that it is researching and developing a new type of perovskite quantum dots. Fuji stated that the half width of their emission spectra is substantially narrower than that of InP; this property could very beneficial to the application of the dots in display materials, LED, bio-imaging and more.

emission spectra of perovskite quantum dots under 420 nm of irradiation light

The chemical composition of perovskite quantum dots are either CsPbX3 or CH3NH3PbX3 (X= Cl, Br, I). Their quantum efficiency is 50–80 % and their half width is 15–39 nm. Their base solvent is either hexane or toluene. However, finding alternative solvents is a challenge that is now being addressed.