High‐Performance Flexible Broadband Photodetectors Based on 2D Hafnium Selenosulfide Nanosheets

Rajesh Kumar Ulaganathan, Raman Sankar, Chang‐yu Lin, Raghavan Chinnambedu Murugesan, Kechao Tang, Fang‐cheng Chou

Research output: Contribution to journalArticlepeer-review


2D transition‐metal dichalcogenides have attracted significant interest in recent years due to their multiple degrees of freedom, allowing for tuning their physical properties via band engineering and dimensionality adjustment. The study of ternary 2D hafnium selenosulfide HfSSe (HSS) high‐quality single crystals grown with the chemical vapor transport (CVT) technique is reported. An as‐grown HSS single crystal exhibits excellent phototransistor performance from the visible to the near‐infrared with outstanding stability. A giant photoresponsivity (≈6.4 × 104 A W−1 at 488 nm) and high specific detectivity (≈1014 Jones) are exhibited by a device fabricated by exfoliating single‐crystal HSS of nano‐thickness on a rigid Si/SiO2 substrate. The application of HSS single crystal is extended to yield a sensible flexible photodetector of photoresponsivity up to ≈1.3 A W−1 at 980 nm. The photoresponsivity of CVT‐grown HSS single crystal is significantly larger than those fabricated with other existing Hf‐based chalcogenides. The results suggest that the layered multi‐elemental 2D chalcogenide single crystals hold great promise for future wearable electronics and integrated optoelectronic circuits.
Original languageEnglish
Article number1900794
JournalAdvanced Electronic Materials
Issue number1
Early online date24 Oct 2019
Publication statusPublished - Jan 2020

Bibliographical note

This is the peer reviewed version of the following article: Ulaganathan, R. K., Sankar, R., Lin, C.‐Y., Murugesan, R. C., Tang, K., Chou, F.‐C., High‐Performance Flexible Broadband Photodetectors Based on 2D Hafnium Selenosulfide Nanosheets. Adv. Electron. Mater. 2019, 1900794, which has been published in final form at https://doi.org/10.1002/aelm.201900794.  This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.

Funding: Ministry of Science and Technology of Taiwan. Grant Numbers: MOST‐(106‐2119‐M‐002‐035‐MY3, 108‐2112‐M‐001‐049‐MY2), AIMA‐108L9008
Academia Sinica. Grant Numbers: AS‐SS‐106‐01‐1, NM004).


  • crystal growth
  • flexible optoelectronics
  • photoresponsivity
  • specific detectivity
  • transition metal dichalcogenides


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