Arthur T Knackerbracket has processed the following story:
Researchers have developed a new type of high-efficiency photodetector inspired by the photosynthetic complexes plants use to turn sunlight into energy. Photodetectors are used in cameras, optical communication systems and many other applications to turn photons into electrical signals.
[...] The photosynthetic complexes found in many plants consist of a large light absorbing region that delivers molecular excited state energy to a reaction center where the energy is converted to a charge. While this setup is very efficient, mimicking it requires achieving long-range energy transport in an organic material, which has proven difficult to accomplish.
To achieve this seemingly impossible task, the researchers used unique quasiparticles known as polaritons. In Optica journal, Forrest and colleagues report their new detector, which generates polaritons in an organic thin film.
"A polariton combines a molecular excited state with a photon, giving it both light-like and matter-like properties that allow long-range energy transport and conversion," said Forrest. "This photodetector is one of the first demonstrations of a practical optoelectronic device based on polaritons."
[...] The results showed that the new photodetector is more efficient at converting light to electrical current than a comparable silicon photodiode. It can also gather light from areas about 0.01 mm2 and achieve conversion of light to electrical current over exceptionally long distances of 0.1 nm. This distance is three orders larger than the energy transfer distance of photosynthetic complexes.
Until now, most polaritons have been observed as stationary quasiparticles in closed cavities with highly reflective mirrors on both top and bottom. The new work revealed important insights into how polaritons propagate in open structures with a single mirror. The new device also allowed the first measurements of how efficiently incident photons can be converted to polaritons.
"Our work shows that polaritons, in addition to being interesting science, are also a goldmine of applications yet to be discovered," said Forrest. "Devices such as ours provide an unusual, and possibly unique, method to understand the fundamental properties of polaritons and to enable yet to be imagined ways to manipulate light and charge."
Journal Reference:
Bin Liu, Xinjing Huang, Shaocong Hou, et al. Photocurrent generation following long-range propagation of organic exciton–polaritons [open], Optica 9, 9, 2022. DOI: 10.1364/OPTICA.461025
(Score: 2) by ChrisMaple on Friday September 09 2022, @03:31AM
0.1 nm is 1 Angstrom, 10^-10 m, smaller than most atoms. Much smaller than 1 wavelength of visible light.