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  • Review Article
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High-performance Ge-on-Si photodetectors

Abstract

The past decade has seen rapid progress in research into high-performance Ge-on-Si photodetectors. Owing to their excellent optoelectronic properties, which include high responsivity from visible to near-infrared wavelengths, high bandwidths and compatibility with silicon complementary metal–oxide–semiconductor circuits, these devices can be monolithically integrated with silicon-based read-out circuits for applications such as high-performance photonic data links and infrared imaging at low cost and low power consumption. This Review summarizes the major developments in Ge-on-Si photodetectors, including epitaxial growth and strain engineering, free-space and waveguide-integrated devices, as well as recent progress in Ge-on-Si avalanche photodetectors.

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Figure 1: Transmission electron microscope cross-sections of Ge-on-Si layers for Ge epitaxial growth at different temperatures.
Figure 2: The effect of tensile strain on the band structure of Ge.
Figure 3: Selective growth of germanium.
Figure 4: Product of bandwidth and quantum efficiency as a function of detector area for different Ge detector designs at an operating wavelength of 1,550 nm.
Figure 5: Ge/Si APD design and performance.

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Correspondence to Jurgen Michel.

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Michel, J., Liu, J. & Kimerling, L. High-performance Ge-on-Si photodetectors. Nature Photon 4, 527–534 (2010). https://doi.org/10.1038/nphoton.2010.157

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