IR-Enhancing Surface Structures Compared

IEEE Spectrum: TED publishes UCD and W&WSens Devices invited paper on light-bending microstructures to enhance PD QE and IR sensitivity "A New Paradigm in High-Speed and High-Efficiency Silicon Photodiodes for Communication—Part I: Enhancing Photon–Material Interactions via Low-Dimensional Structures" by Hilal Cansizoglu, Ekaterina Ponizovskaya Devine, Yang Gao, Soroush Ghandiparsi, Toshishige Yamada, Aly F. Elrefaie, Shih-Yuan Wang, and M. Saif Islam.

"[Saif] Islam and his colleagues came up with a silicon structure that makes photodiodes both fast and efficient by being both thin and good at capturing light. The structure is an array of tapered holes in the silicon that have the effect of steering the light into the plane of the silicon. “So basically, we’re bending light 90 degrees,” he says."

The paper compares the proposed approach with other surface structures for IR sensitivity enhancement: