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Graduate Student Seminar - 04/28/2017

"Imaging Beyond the Bandgap with Hot-Carrier Silicon Photodetectors"

by Lisa Krayer

Friday, April 28, 2017 -- 12:00 p.m.
Large Conference Room, 1207 Energy Research Facility

Advisor:  Asst. Prof. Jeremy Munday

Expanding the bandwidth of silicon detectors is advantageous for many applications requiring optical energy conversion because silicon is a well understood, naturally abundant and relatively inexpensive material. Hot carriers generated from photons below silicon’s bandgap in metal contacts can reduce the effective bandgap to the Schottky barrier height because of current injection through the metal-semiconductor interface. However, for efficient photodetection the metal must be highly absorptive at long wavelengths and ultra-thin in order for the hot carriers to reach the Schottky interface with enough energy to traverse the barrier. Previous hot carrier photodetectors have required complicated nanostructuring to meet these requirements, increasing their fabrication cost which could prohibit their integration into commercial device design. I will present a cost effective, lithography free hot carrier photodetector that absorbs ~ 80% of broadband IR radiation in a planar, nanoscale back contact to silicon. The simplicity of the high absorption phenomenon promises straightforward incorporation into commercial silicon device fabrication.

For additional information about the IREAP Graduate Student Seminars, contact Linus Feder.

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