Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Semiconductor-free microelectronics are now possible, thanks to metamaterials

08.11.2016

Engineers at the University of California San Diego have fabricated the first semiconductor-free, optically-controlled microelectronic device. Using metamaterials, engineers were able to build a microscale device that shows a 1,000 percent increase in conductivity when activated by low voltage and a low power laser.

The discovery paves the way for microelectronic devices that are faster and capable of handling more power, and could also lead to more efficient solar panels. The work was published Nov. 4 in Nature Communications.


This is the designed semiconductor-free microelectronic device.

Credit: UC San Diego Applied Electromagnetics Group


These are scanning electron micrograph images of the semiconductor-free microelectronic device (top left) and the gold metasurface (top right, bottom).

Credit: UC San Diego Applied Electromagnetics Group

The capabilities of existing microelectronic devices, such as transistors, are ultimately limited by the properties of their constituent materials, such as their semiconductors, researchers said.

For example, semiconductors can impose limits on a device's conductivity, or electron flow. Semiconductors have what's called a band gap, meaning they require a boost of external energy to get electrons to flow through them. And electron velocity is limited, since electrons are constantly colliding with atoms as they flow through the semiconductor.

A team of researchers in the Applied Electromagnetics Group led by electrical engineering professor Dan Sievenpiper at UC San Diego sought to remove these roadblocks to conductivity by replacing semiconductors with free electrons in space. "And we wanted to do this at the microscale," said Ebrahim Forati, a former postdoctoral researcher in Sievenpiper's lab and first author of the study.

However, liberating electrons from materials is challenging. It either requires applying high voltages (at least 100 Volts), high power lasers or extremely high temperatures (more than 1,000 degrees Fahrenheit), which aren't practical in micro- and nanoscale electronic devices.

To address this challenge, Sievenpiper's team fabricated a microscale device that can release electrons from a material without such extreme requirements. The device consists of an engineered surface, called a metasurface, on top of a silicon wafer, with a layer of silicon dioxide in between. The metasurface consists of an array of gold mushroom-like nanostructures on an array of parallel gold strips.

The gold metasurface is designed such that when a low DC voltage (under 10 Volts) and a low power infrared laser are both applied, the metasurface generates "hot spots"--spots with a high intensity electric field--that provide enough energy to pull electrons out from the metal and liberate them into space.

Tests on the device showed a 1,000 percent change in conductivity. "That means more available electrons for manipulation," Ebrahim said.

"This certainly won't replace all semiconductor devices, but it may be the best approach for certain specialty applications, such as very high frequencies or high power devices," Sievenpiper said.

According to researchers, this particular metasurface was designed as a proof-of-concept. Different metasurfaces will need to be designed and optimized for different types of microelectronic devices.

"Next we need to understand how far these devices can be scaled and the limits of their performance," Sievenpiper said. The team is also exploring other applications for this technology besides electronics, such as photochemistry, photocatalysis, enabling new kinds of photovoltaic devices or environmental applications.

###

Full paper: "Photoemission-based microelectronic devices." Authors of the study are Ebrahim Forati, Tyler J. Dill, Andrea R. Tao and Dan Sievenpiper.

This work was funded by Defense Advanced Research Projects Agency (grant N00014-13-1-0618) and the Office of Naval Research Defense University Research Instrumentation Program (grant N00014-13-1-0655).

Media Contact

Liezel Labios
llabios@ucsd.edu
858-246-1124

 @UCSanDiego

http://www.ucsd.edu 

Liezel Labios | EurekAlert!

More articles from Power and Electrical Engineering:

nachricht Materials that can revolutionize how light is harnessed for solar energy
20.08.2019 | Columbia University

nachricht A miniature stretchable pump for the next generation of soft robots
15.08.2019 | Ecole Polytechnique Fédérale de Lausanne

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Quantum computers to become portable

Together with the University of Innsbruck, the ETH Zurich and Interactive Fully Electrical Vehicles SRL, Infineon Austria is researching specific questions on the commercial use of quantum computers. With new innovations in design and manufacturing, the partners from universities and industry want to develop affordable components for quantum computers.

Ion traps have proven to be a very successful technology for the control and manipulation of quantum particles. Today, they form the heart of the first...

Im Focus: Towards an 'orrery' for quantum gauge theory

Experimental progress towards engineering quantized gauge fields coupled to ultracold matter promises a versatile platform to tackle problems ranging from condensed-matter to high-energy physics

The interaction between fields and matter is a recurring theme throughout physics. Classical cases such as the trajectories of one celestial body moving in the...

Im Focus: A miniature stretchable pump for the next generation of soft robots

Soft robots have a distinct advantage over their rigid forebears: they can adapt to complex environments, handle fragile objects and interact safely with humans. Made from silicone, rubber or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments.

Most soft robots are actuated by rigid, noisy pumps that push fluids into the machines' moving parts. Because they are connected to these bulky pumps by tubes,...

Im Focus: Vehicle Emissions: New sensor technology to improve air quality in cities

Researchers at TU Graz are working together with European partners on new possibilities of measuring vehicle emissions.

Today, air pollution is one of the biggest challenges facing European cities. As part of the Horizon 2020 research project CARES (City Air Remote Emission...

Im Focus: Self healing robots that "feel pain"

Over the next three years, researchers from the Vrije Universiteit Brussel, University of Cambridge, École Supérieure de Physique et de Chimie Industrielles de la ville de Paris (ESPCI-Paris) and Empa will be working together with the Dutch Polymer manufacturer SupraPolix on the next generation of robots: (soft) robots that ‘feel pain’ and heal themselves. The partners can count on 3 million Euro in support from the European Commission.

Soon robots will not only be found in factories and laboratories, but will be assisting us in our immediate environment. They will help us in the household, to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The power of thought – the key to success: CYBATHLON BCI Series 2019

16.08.2019 | Event News

4th Hybrid Materials and Structures 2020 28 - 29 April 2020, Karlsruhe, Germany

14.08.2019 | Event News

What will the digital city of the future look like? City Science Summit on 1st and 2nd October 2019 in Hamburg

12.08.2019 | Event News

 
Latest News

Shape-shifting sheets

21.08.2019 | Materials Sciences

Study reveals profound patterns in globally important algae

21.08.2019 | Life Sciences

New tools to minimize risks in shared, augmented-reality environments

21.08.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>