Multimodal Photodiode and Phototransistor Device Based on Two-Dimensional Materials

Seon Namgung, Jonah Shaver, Sang Hyun Oh, Steven J. Koester

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


With strong light-matter interaction in their atomically thin layered structures, two-dimensional (2D) materials have been widely investigated for optoelectronic applications such as photodetectors and photovoltaic devices. Depending on the aim of optoelectronic applications, different device structures have been employed. Lateral phototransistor structures have been employed for high optical gain, while vertical photodiode structures have been employed for fast response and low power operation. Herein, we demonstrate a multimodal photodetector platform based on 2D materials, combining both a phototransistor and a photodiode and taking the corresponding desirable characteristics from each structure within a single device. In this platform, a multilayered transition-metal dichalcogenide flake is transferred on top of metal electrodes, and a transparent gate electrode is employed. The channel region of the flake between electrodes operates as a phototransistor providing a high gain mode, while the electrode region in the same flake operates as a vertical Schottky photodiode providing a fast response mode. These modes can be dynamically selected by controlling the drain voltage and gate voltage.

Original languageEnglish (US)
Pages (from-to)10500-10506
Number of pages7
JournalACS nano
Issue number11
StatePublished - Nov 22 2016

Bibliographical note

Funding Information:
This work was supported primarily by the Air Force Office of Scientific Research under award no. FA9550-14-1-0277 (S.N., S.J.K.) This work was also supported in part by the National Science Foundation (NSF) through the University of Minnesota MRSEC under award no. DMR-1420013 (J.S., S.?H.O., S.J.K.). Device fabrication was performed at the Minnesota Nanofabrication Center at the University of Minnesota, which receives partial support from the NSF through the National Nanotechnology Coordinated Infrastructure (NNCI). Portions of this work were also carried out in the University of Minnesota Characterization Facility, which received capital equipment funding from the NSF MRSEC.

Publisher Copyright:
© 2016 American Chemical Society.


  • 2D materials
  • multimodal
  • photodiode
  • phototransistor
  • Schottky barrier

MRSEC Support

  • Partial

PubMed: MeSH publication types

  • Journal Article


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