Near-infrared photoresponse in ge/si quantum dots enhanced by photon-trapping hole arrays

Andrew I. Yakimov, Victor V. Kirienko, Aleksei A. Bloshkin, Dmitrii E. Utkin, Anatoly V. Dvurechenskii

Research output: Contribution to journalArticlepeer-review

Abstract

Group-IV photonic devices that contain Si and Ge are very attractive due to their compatibility with integrated silicon photonics platforms. Despite the recent progress in fabrication of Ge/Si quantum dot (QD) photodetectors, their low quantum efficiency still remains a major challenge and different approaches to improve the QD photoresponse are under investigation. In this paper, we report on the fabrication and optical characterization of Ge/Si QD pin photodiodes integrated with photon-trapping microstructures for near-infrared photodetection. The photon traps represent vertical holes having 2D periodicity with a feature size of about 1 µm on the diode surface, which significantly increase the normal incidence light absorption of Ge/Si QDs due to generation of lateral optical modes in the wide telecommunication wavelength range. For a hole array periodicity of 1700 nm and hole diameter of 1130 nm, the responsivity of the photon-trapping device is found to be enhanced by about 25 times at λ = 1.2 µm and by 34 times at λ ≈ 1.6 µm relative to a bare detector without holes. These results make the micro/nanohole Ge/Si QD photodiodes promising to cover the operation wavelength range from the telecom O-band (1260–1360 nm) up to the L-band (1565–1625 nm).

Original languageEnglish
Article number2302
JournalNanomaterials
Volume11
Issue number9
DOIs
Publication statusPublished - Sep 2021

Keywords

  • Near-infrared photodetection
  • Photon-trapping nanostructures
  • Quantum dots
  • Telecom

OECD FOS+WOS

  • 2.04 CHEMICAL ENGINEERING
  • 2.05 MATERIALS ENGINEERING
  • 1.03 PHYSICAL SCIENCES AND ASTRONOMY

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