Research Team Realizes 3-Color Photo­de­tec­tor

SEM pictures of processed single element devices (Source: A. M. Hoang et al. / Sci .Rep.)

SEM pictures of processed single element devices (Source: A. M. Hoang et al. / NPG)

While infrared waves are available in short, mid, and long lengths, most detection devices are unable to harness all three at the same time. Now North­western University’s Manijeh Razeghi and her team have developed a new approach in device design to realize a three-color, shortwave-midwave-longwave infrared photo­detector. With the new design, the devices can detect different infrared wavebands by simply varying the applied bias voltage. This could open up a range of potential appli­cations, including infrared color tele­visions and three-color infrared imaging.

“A device capable of detecting different infrared wavebands is highly desirable in the next generation infrared imaging systems,” said Razeghi, Walter P. Murphy Professor of Electrical Engineering and Computer Science in North­western’s McCormick School of Engineering. Led by her, the researchers invented and investigated the new design for three-color photodiodes without using additional terminal contacts. The resulting photo­detector is based on indium-arsenide/gallium-anti­monide/aluminum-anti­monide type-II super­lattices.

As the applied bias voltage varies, the photo­detector sequentially exhibits the behavior of three different colors, corres­ponding to the bandage of three absorbers, and achieves well-defined cut-off wave­lengths and high-quantum efficiency in each channel. This new research builds on the Razeghi group’s many years of work in North­western’s Center for Quantum Devices, including the development of the first single-color, short-wave­length infrared photo­detector and two-color, shortwave-midwave infrared photo­detector based on type-II super­lattices. “I am fascinated by these results,” Razeghi said. “The initial success in this demon­stration will drive us to the new frontier of infrared detection and imaging techno­logy.” (Source: NWU)

Reference: A. M. Hoang et al.: High performance bias-selectable three-color Short-wave/Mid-wave/Long-wave Infrared Photodetectors based on Type-II InAs/GaSb/AlSb superlattices, Sci. Rep. 6, 24144 (2016), DOI: 10.1038/srep24144 

Link: Center for Quantum Devices (M. Razeghi), Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, USA

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