A team of electrical engineers from University of Wisconsin-Madison has developed the fastest, most responsive flexible silicon phototransistor ever made.

The researchers claim that the new phototransistor could boost the performance of several products, including digital cameras, night-vision goggles and smoke detectors to surveillance systems and satellites.

It is notable that all these devices rely on electronic light sensors.

When the new phototransistor is integrated into a digital camera lens, it could reduce bulkiness and boost both the acquisition speed and quality of video or still photos.

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

The findings of the study were published in the journal Advanced Optical Materials.

Phototransistors work just like human eyes and can sense and collect light, then convert that light into an electrical charge proportional to its intensity and wavelength.

Majority of phototransistors are fabricated on rigid surfaces and are flat but the latest phototransistor is flexible, meaning they are more capable of mimicking 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 they invert the finished phototransistor onto a plastic substrate.

"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 said. "There's a built-in capability to sense weak light," he added.

"This demonstration shows great potential in high-performance and flexible photodetection systems. It shows the capabilities of high-sensitivity photodetection and stable performance under bending conditions, which have never been achieved at the same time," concluded Ma.