Researchers achieve nearly 90% efficiency converting light energy into surface waves on graphene

Scientists at Russia-based MIPT and Vladimir State University have reported a nearly 90% efficiency converting light energy into surface waves on graphene. They relied on a laser-like energy conversion scheme and collective resonances.

he structure for converting laser light to surface-plasmon polaritons image

Manipulating light at the nanoscale is crucial for creating ultracompact devices for optical energy conversion and storage. To localize light on such a small scale, researchers convert optical radiation into so-called surface plasmon-polaritons. These SPPs are oscillations propagating along the interface between two materials with drastically different refractive indices — specifically, a metal and a dielectric or air. Depending on the materials chosen, the degree of surface wave localization varies. It is the strongest for light localized on a material only one atomic layer thick, because such 2D materials have high refractive indices.

New type of graphene photodetector could enable low-cost cameras for self-driving cars and robots

An international team of researchers recently reported its success in creating a new type of graphene-based photodetector.

The team integrated three concepts to achieve the new device: metallic plasmonic antennas, ultra sub-wavelength waveguiding of light and graphene photodetection. Specifically, the 2D-material hexagonal boron nitride was used as the waveguide for hyperbolic phonon polaritons, which can highly confine and guide mid-infrared light at the nanoscale. By carefully matching the nano-antenna with the phonon polariton waveguide, they efficiently funnel incoming light into a nanoscale graphene junction. By using this approach, they were able to overcome intrinsic limitations of graphene, such as its low absorption and its small photoactive region near the junction.

New twist on graphene to boost optoelectronics

Researchers at University of California Berkeley, Washington University in St. Louis and Lawrence Berkeley National Laboratory have stacked two sheets of graphene on top of each other and twisted them, which resulted in the conversion of a common linear material into one with nonlinear optical capabilities. This could prove useful for various everyday technologies — from spectroscopy and material analysis to communications and computing.

In the study of optics, scientists distinguish between linear and nonlinear materials. Most materials, including sheets of graphene, are linear. If you shine red light at a sheet of graphene, the photons will either be absorbed or scattered, but in any case - they will remain red.

Graphene-enhanced color-changing flexible photonic crystals could be the key to next-gen smart sensors

An international team of scientists, led by the Universities of Surrey and Sussex, has developed graphene-enhanced color-changing, flexible photonic crystals that could be used to develop sensors that warn when an earthquake might strike next.

Optical images and internal microstructure of graphene-enhanced colloidal crystals imageOptical images and internal microstructure of colloidal crystals enhanced with graphene. Image from Advanced Functional Materials

The wearable, robust and low-cost sensors can respond sensitively to light, temperature, strain or other physical and chemical stimuli making them an extremely promising option for cost-effective smart visual sensing applications in a range of sectors including healthcare and food safety.

A new experimental pilot line will integrate graphene and related layered materials (GRMs) in semiconductor platforms

​The European Commission recently invited a group of Graphene Flagship partners and associated members to set up an experimental pilot line to integrate graphene and related layered materials (GRMs) in semiconductor platforms.

The project aims to establish a European ecosystem covering the entire value chain, from tool manufacturers and chemical and material providers to pilot lines. This collaborative project will pioneer the manufacture of new prototype electronics, photonics and sensors integrating GRMs. The 2D Experimental Pilot Line (2D-EPL) will offer prototyping services to companies, research centers and academics to develop their innovative technologies based on 2D materials in an established processing platform.