Waveguide-integrated mid-IR photodetector and all-optical modulator based on interlayer excitons absorption in a WS2/HfS2heterostructure

Shahar Edelstein, S. R.K.Chaitanya Indukuri, Noa Mazurski, Uriel Levy*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Novel 2D van der Waals semiconductors facilitate the formation of heterostructures and thus support bandgap engineering for atomically thin modern photonic applications. When these heterostructures form a type II band structure, interlayer excitons (ILEs) are formed as a result of the ultrafast charge transfer between the layers. Here, we present for the first time a waveguide-coupled, mid-IR photodetector and modulator based on the ILE absorption. The device consists of a heterostructure of a single layer of tungsten disulfide (WS2) and a few layers of hafnium disulfide (HfS2) integrated to a silicon waveguide on a sapphire substrate. We measure broadband mid-IR photodetection (3.8-5.5 μm) with responsivity in the order of tens of μA/W and with no significant effect on the waveguide's transmission. Additionally, we demonstrate waveguide-integrated, mid-IR, all-optical modulation by controlling the ILE population with the interband transition of the individual layers of the heterostructure.

Original languageAmerican English
Pages (from-to)4337-4345
Number of pages9
Issue number19
StatePublished - 4 Sep 2022

Bibliographical note

Publisher Copyright:
© 2022 the author(s), published by De Gruyter, Berlin/Boston.


  • 2D TMDC materials and heterostructures
  • integrated mid-IR photodetector
  • interlayer exciton
  • silicon and integrated photonics


Dive into the research topics of 'Waveguide-integrated mid-IR photodetector and all-optical modulator based on interlayer excitons absorption in a WS2/HfS2heterostructure'. Together they form a unique fingerprint.

Cite this