Near-infrared germanium PIN-photodiodes with >1A/W responsivity
2025

High Responsivity Near-Infrared Germanium Photodiodes

publication Evidence: high

Author Information

Author(s): Liu Hanchen, Pasanen Toni P., Fung Tsun Hang, Isometsä Joonas, Haarahiltunen Antti, Hesse Steven, Werner Lutz, Vähänissi Ville, Savin Hele

Primary Institution: Aalto University, Department of Electronics and Nanoengineering, Espoo, Finland

Hypothesis

Can a nanoengineered PIN-photodiode made of CMOS-compatible germanium achieve high external quantum efficiency over a wide wavelength range?

Conclusion

The study demonstrates that the new germanium photodiode design achieves high external quantum efficiency and low dark current, making it suitable for various applications.

Supporting Evidence

  • The photodiode achieves an external quantum efficiency above 90% over a wide wavelength range.
  • The responsivity at 1.55 µm is 1.15 A/W, which is higher than traditional germanium photodiodes.
  • The dark current density is lower than previously reported for germanium photodiodes.
  • The integration of nanostructures minimizes optical losses and enhances performance.

Takeaway

Scientists created a special type of light sensor using germanium that can see a lot of different colors of light really well, even better than older sensors.

Methodology

The photodiodes were fabricated using atomic layer deposition and nanostructuring techniques to enhance performance.

Limitations

The study does not address potential challenges in scaling the fabrication process for commercial applications.

Digital Object Identifier (DOI)

10.1038/s41377-024-01670-4

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