Hourglass-Shaped Silicon Photodiodes Provide Greater Sensitivity

A team of researchers from Pohang University of Science and Technology have developed near-infrared (NIR) photodiodes from silicon that are approximately one-third more sensitive than existing photodiodes. Existing NIR photodiodes are typically made of chemical materials that require separate cooling devices and are difficult to integrate. The researchers, led by professor Chang-Ki Baek, used hourglass-shaped silicon nanowires to increase silicon’s absorption of NIR light. Courtesy of Pohang University of Science and Technology. The upper inverted nanocone of the nanowires increases absorption probability by extending the dwell time of NIR-SWIR photons via the generation of whispering-gallery-mode resonances, whereas the...