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.

Researchers develop a graphene metamaterial film that absorbs sunlight with minimal heat loss

Researchers from Swinburne University developed a graphene-based highly efficient solar absorbing film that absorbs sunlight with minimal heat loss. The film rapidly heats up in an open environment and has great potential in solar thermal energy harvesting systems - in addition to other applications such as thermophotovoltaics (directly converting heat to electricity), solar seawater desalination, light emitters and photodetectors.

30nm graphene-metamaterial heat-absorbing film photo

This is the 2nd-generation material developed by the same group - now with a thickness of only 30 nm and improved performance and longer lifetime. The researchers have now created a first prototype and also suggest a scalable low-cost manufacturing process.

New graphene-based metasurface capable of independent amplitude and phase control of light

A KAIST research team in collaboration with the University of Wisconsin-Madison theoretically developed a graphene-based active metasurface capable of independent amplitude and phase control of mid-infrared light. This research gives a new insight into modulating the mid-infrared wavefront with high resolution by solving the problem of the independent control of light amplitude and phase, which has remained a long-standing challenge.

Light modulation technology is essential for developing future optical devices such as holography, high-resolution imaging, and optical communication systems. Liquid crystals and a microelectromechanical system (MEMS) have previously been utilized to modulate light. However, both methods suffer from significantly limited driving speeds and unit pixel sizes larger than the diffraction limit, which consequently prevent their integration into photonic systems.