Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UW-Madison engineers reveal record-setting flexible phototransistor

02.11.2015

Inspired by mammals' eyes, University of Wisconsin-Madison electrical engineers have created the fastest, most responsive flexible silicon phototransistor ever made.


Developed by UW-Madison electrical engineers, this unique phototransistor is flexible, yet faster and more responsive than any similar phototransistor in the world.

Credit: Jung-Hun Seo

The innovative phototransistor could improve the performance of myriad products -- ranging from digital cameras, night-vision goggles and smoke detectors to surveillance systems and satellites -- that rely on electronic light sensors. Integrated into a digital camera lens, for example, it could reduce bulkiness and boost both the acquisition speed and quality of video or still photos.

Developed by UW-Madison collaborators Zhenqiang "Jack" Ma, professor of electrical and computer engineering, and research scientist Jung-Hun Seo, the high-performance phototransistor far and away exceeds all previous flexible phototransistor parameters, including sensitivity and response time.

The researchers published details of their advance this week in the journal Advanced Optical Materials.

Like human eyes, phototransistors essentially sense and collect light, then convert that light into an electrical charge proportional to its intensity and wavelength. In the case of our eyes, the electrical impulses transmit the image to the brain. In a digital camera, that electrical charge becomes the long string of 1s and 0s that create the digital image.

While many phototransistors are fabricated on rigid surfaces, and therefore are flat, Ma and Seo's are flexible, meaning they more easily mimic the behavior of mammalian eyes.

"We actually can make the curve any shape we like to fit the optical system," Ma says. "Currently, there's no easy way to do that."

One important aspect of the success of the new phototransistors is the researchers' innovative "flip-transfer" fabrication method, in which their final step is to invert the finished phototransistor onto a plastic substrate. At that point, a reflective metal layer is on the bottom.

"In this structure -- unlike other photodetectors -- light absorption in an ultrathin silicon layer can be much more efficient because light is not blocked by any metal layers or other materials," Ma says.

The researchers also placed electrodes under the phototransistor's ultrathin silicon nanomembrane layer -- and the metal layer and electrodes each act as reflectors and improve light absorption without the need for an external amplifier.

"There's a built-in capability to sense weak light," Ma says.

Ultimately, the new phototransistors open the door of possibility, he says.

"This demonstration shows great potential in high-performance and flexible photodetection systems," says Ma, whose work was supported by the U.S. Air Force. "It shows the capabilities of high-sensitivity photodetection and stable performance under bending conditions, which have never been achieved at the same time."

###

The researchers are patenting the technology through the Wisconsin Alumni Research Foundation.

CONTACT: Zhenqiang "Jack" Ma, (608) 261-1095, mazq@engr.wisc.edu

Renee Meiller, (608) 262-2481, meiller@engr.wisc.edu

Media Contact

Zhenqiang 'Jack' Ma
mazq@engr.wisc.edu
608-261-1095

 @UWMadScience

http://www.wisc.edu 

Zhenqiang 'Jack' Ma | EurekAlert!

More articles from Information Technology:

nachricht Reversing cause and effect is no trouble for quantum computers
20.07.2018 | Centre for Quantum Technologies at the National University of Singapore

nachricht Study suggests buried Internet infrastructure at risk as sea levels rise
18.07.2018 | University of Wisconsin-Madison

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

The Maturation Pattern of the Hippocampus Drives Human Memory Deve

23.07.2018 | Science Education

FAU researchers identify Parkinson's disease as a possible autoimmune disease

23.07.2018 | Health and Medicine

O2 stable hydrogenases for applications

23.07.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>