Doing photon upconversion a solid: Crystals that convert light to more useful wavelengths

https://phys.org/news/2021-11-photon-upconversion-solid-crystals-wavelengths.html

"transform presently wasted long-wavelength light into more useful shorter wavelength... exploring materials to realize photon upconversion (PUC), by which photons with lower energies (longer wavelengths) are captured and re-emitted as photons with higher energies (shorter wavelengths). One promising way to realize this is through triplet-triplet annihilation (TTA)... findings pave the way for many novel photonic technologies, such as better solar cells and photocatalysts for hydrogen and hydrocarbon productions"

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Solid material that 'upconverts' visible light photons to UV light photons could change how we utilize sunlight

https://phys.org/news/2023-01-solid-material-upconverts-visible-photons.html

Dark singlet exciton sensitized triplet energy transfer realized across CsPbBr3 nanoplate-organic interface

https://phys.org/news/2023-02-dark-singlet-exciton-sensitized-triplet.html