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Research illuminates the path to superior electro-optic performance in aluminum scandium nitride alloys

From integrated photonics to quantum information science, the ability to control light with electric fields—a phenomenon known as the electro-optic effect—supports vital applications such as light modulation and frequency transduction. These components rely on nonlinear optical materials, in which light waves can be manipulated by applying electric fields.

Conventional nonlinear optical materials such as lithium niobate have a large electro-optic response but are hard to integrate with silicon devices. In the search for silicon-compatible materials, aluminum scandium nitride (AlScN), which had already been flagged as an excellent piezoelectric—referring to a material’s ability to generate electricity when pressure is applied, or to deform when an electric field is applied—has come to the fore. However, better control of its properties and means to enhance its electro-optic coefficients are still required.

Researchers in Chris Van de Walle’s computational materials group at UC Santa Barbara have now uncovered ways to achieve these goals. Their study, published in Applied Physics Letters, explains how adjusting the material’s atomic structure and composition can boost its performance. Strong electro-optic response requires a large concentration of scandium—but the specific arrangement of the scandium atoms within the AlN crystal lattice matters.

Material’s ‘incipient ferroelectricity’ could jumpstart fast, low-power electronics

Scientists at Penn State have harnessed a unique property called incipient ferroelectricity to create a new type of computer memory that could revolutionize how electronic devices work, such as using much less energy and operating in extreme environments like outer space.

They published their work, which focuses on multifunctional two-dimensional field-effect transistors (FETs), in Nature Communications. FETs are advanced electronic devices that use ultra-thin layers of materials to control , offering multiple functions like switching, sensing or memory in a compact form.

They are ferroelectric-like, meaning the direction of their electric conduction can be reversed when an external electric field is applied to the system. FETs are essential in computing, since the ferroelectric-like property allows them to shift signals.

Mesoporous silicon: Etching technique reveals unique electronic transport properties

Silicon is the best-known semiconductor material. However, controlled nanostructuring drastically alters the material’s properties. Using a specially developed etching apparatus, a team at HZB has now produced mesoporous silicon layers with countless tiny pores and investigated their electrical and thermal conductivity.

For the first time, the researchers elucidated the electronic transport mechanism in this mesoporous silicon. The material has great potential for applications and could also be used to thermally insulate qubits for quantum computers. The work is published in Small Structures.

Mesoporous silicon is with disordered nanometer-sized pores. The material has a huge internal surface area and is also biocompatible. This opens up a wide range of potential applications, from biosensors to battery anodes and capacitors. In addition, the material’s exceptionally low thermal conductivity suggests applications as thermal insulator.

Scientists design novel battery that runs on atomic waste

Researchers have developed a battery that can convert nuclear energy into electricity via light emission, a new study suggests.

Nuclear power plants, which generate about 20% of all electricity produced in the United States, produce almost no greenhouse gas emissions. However, these systems do create , which can be dangerous to human health and the environment. Safely disposing of this waste can be challenging.

Using a combination of scintillator crystals, high-density materials that emit light when they absorb radiation, and , the team, led by researchers from The Ohio State University, demonstrated that ambient gamma radiation could be harvested to produce a strong enough electric output to power microelectronics, like microchips.

DNA origami suggests route to reusable, multifunctional biosensors

Using an approach called DNA origami, scientists at Caltech have developed a technique that could lead to cheaper, reusable biomarker sensors for quickly detecting proteins in bodily fluids, eliminating the need to send samples out to lab centers for testing.

“Our work provides a proof-of-concept showing a path to a single-step method that could be used to identify and measure and proteins,” says Paul Rothemund (BS ‘94), a visiting associate at Caltech in computing and mathematical sciences, and computation and neural systems.

A paper describing the work recently appeared in the journal Proceedings of the National Academy of Sciences. The lead authors of the paper are former Caltech postdoctoral scholar Byoung-jin Jeon and current graduate student Matteo M. Guareschi, who completed the work in Rothemund’s lab.

Hybrid states of light and matter may significantly enhance OLED brightness

Researchers developed a theoretical model that predicts a substantial increase in the brightness of organic light-emitting diodes (OLEDs) by leveraging novel quantum states called polaritons. Integrating polaritons into OLEDs effectively requires the discovery of new materials, making practical implementation an exciting challenge.

OLED technology has become a common light source in a variety of high-end display devices, such as smartphones, laptops, TVs or smart watches.

While OLEDs are rapidly reshaping lighting applications with their flexibility and eco-friendliness, they can be quite slow at converting electric current into light, with only a 25% probability in emitting photons efficiently and rapidly. The latter is an important condition for boosting the brightness of OLEDs, which tend to be dimmer than other light technologies.

Scientists reveal key to affordable, room-temperature quantum light

Quantum light sources are fickle. They can flicker like stars in the night sky and can fade out like a dying flashlight. However, newly published research from the University of Oklahoma proves that adding a covering to one of these light sources, called a colloidal quantum dot, can cause them to shine without faltering, opening the door to new, affordable quantum possibilities. The findings are available in Nature Communications.

Quantum dots, or QDs, are so small that if you scaled up a single quantum dot to the size of a baseball, a baseball would be the size of the moon. QDs are used in a variety of products, from computer monitors and LEDs to and biomedical engineering devices. They are also used in and communication.

A research study led by OU Assistant Professor Yitong Dong demonstrates that adding a crystalized molecular layer to QDs made of perovskite neutralizes surface defects and stabilizes the surface lattices. Doing so prevents them from darkening or blinking.

Searching for a universal principle for unconventional superconductivity

You may recognize graphite as the “lead” in a pencil, but besides helping you take notes or fill in countless bubbles on exam answer sheets, it is helping scientists grapple with the secrets of superconductivity.

Superconductivity happens when an electric current is transmitted through wires without the loss of any energy in the form of heat or resistance. Superconducting materials have the potential to revolutionize many aspects of our daily lives, from improving the electrical grid to making more powerful computers.

However, generally requires very low temperatures, so low they may become impractical, and the exact mechanisms of superconductivity are not well understood for many .

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