Flexible phototransistor sets performance records
Unlike many phototransistors that are fabricated on rigid surfaces, the new device is based on a transferrable single-crystalline silicon nanomembrane on top of a polymer substrate. Being flexible, say the researchers, means their phototransistor "more easily mimics the behavior of mammalian eyes," while the silicon nanomembrane as the top layer enables more efficient light sensing than with other photodetectors.
"We actually can make the curve any shape we like to fit the optical system," says professor of electrical and computer engineering, Zhenqiang "Jack" Ma. "Currently, there’s no easy way to do that."
The performance of the new phototransistor is said to exceed the parameters – including sensitivity and response time – of all previous such devices. As a result, it offers the potential to improve a variety of electronic light sensing-based products and applications.
For example, say the researchers, if integrated into a digital camera lens the flexible phototransistor could both reduce its size and improve acquisition speed and quality of video or photos. Other potential applications include night-vision goggles and surveillance systems, as well as smoke detectors and satellites.
"This demonstration shows great potential in high-performance and flexible photodetection systems," says Ma. "It shows the capabilities of high-sensitivity photodetection and stable performance under bending conditions, which have never been achieved at the same time."
For more, see the paper published in the journal Advanced Optical Materials: Flexible Phototransistors Based on Single-Crystalline Silicon Nanomembranes.