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arXiv · 1909.12675

Giant enhancement of silicon plasmonic SWIR photodetection using nanoscale self-organised metallic films

Christian Frydendahl·Meir Grajower·Jonathan Bar-David·Noa Mazurski·Joseph Shappir·Uriel Levy
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Abstract

Many consumer technologies and scientific methods rely on photodetection of infrared light. We report a Schottky photodetector operating below silicon's band gap energy, through hot carrier injection from a nanoscale metallic absorber. Our design relies on simple CMOS-compatible 'bottom up' fabrication of fractally nanostructured aluminium films. Due to the fractal nature of the nanostructuring, the aluminium films support plasmonically enhanced absorption over a wide wavelength range. We demonstrate two orders of magnitude improvements of responsivity, noise-equivalent-power, and detectivity as compared to bulk metal, over a broad spectral and angular range. We attribute this to momentum relaxation processes from the nanoscale fractal geometry. Specifically, we demonstrate a direct link between quantum efficiency enhancement and structural parameters such as perimeter to surface ratio. Finally, our devices also function as bulk refractive index sensors. Our approach is a promising candidate for future cost effective and robust short wave infrared photodetection and sensing applications.

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Christian Frydendahl, Meir Grajower, Jonathan Bar-David, Noa Mazurski, Joseph Shappir, Uriel Levy. 2019-09-27. Giant enhancement of silicon plasmonic SWIR photodetection using nanoscale self-organised metallic films. https://doi.org/10.1364/optica.379549

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