High photoresponsivity and broadband photodetection with a band-engineered WSe 2 /SnSe 2 heterostructure

Research output: Contribution to journalArticleScientificpeer-review


Research units

  • VTT Technical Research Centre of Finland
  • Northwest University China


van der Waals (vdW) heterostructures formed by stacking different two-dimensional layered materials have been demonstrated as a promising platform for next-generation photonic and optoelectronic devices due to their tailorable band-engineering properties. Here, we report a high photoresponsivity and broadband photodetector based on a WSe 2 /SnSe 2 heterostructure. By properly biasing the heterostructure, its band structure changes from near-broken band alignment to type-III band alignment which enables high photoresponsivity from visible to telecommunication wavelengths. The highest photoresponsivity and detectivity at 532 nm are ∼588 A W -1 and 4.4 × 10 10 Jones and those at 1550 nm are ∼80 A W -1 and 1.4 × 10 10 Jones, which are superior to those of the current state-of-the-art layered transition metal dichalcogenides based photodetectors under similar measurement conditions. Our work not only provides a new method for designing high-performance broadband photodetectors but also enables a deep understanding of the band engineering technology in the vdW heterostructures possible for other applications, such as modulators and lasers.


Original languageEnglish
Pages (from-to)3240-3247
Number of pages8
Issue number7
Publication statusPublished - 21 Feb 2019
MoE publication typeA1 Journal article-refereed

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