Self-Driven Metal–Semiconductor–Metal WSe2 Photodetector with Asymmetric Contact Geometries

Changjian Zhou, Salahuddin Raju, Bin Li, Mansun Chan, Yang Chai, Cary Y. Yang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

140 Citations (Scopus)


Self-driven photodetectors have wide applications in wireless sensor networks and wearable physiological monitoring systems. While 2D materials have different bandgaps for potential novel application fields, the self-driven photodetectors are mainly built on PN junctions or heterostructures, whose fabrication involves doping or reliable multiple transfer steps. In this study, a novel metal–semiconductor–metal (MSM) WSe2 photodetector with asymmetric contact geometries is proposed. A high responsivity of 2.31 A W−1 is obtained under zero bias, and a large open-circuit voltage of 0.42 V is achieved for an MSM photodetector with a large contact length difference. The MSM photodetector can overcome the disadvantage of high dark current in traditional MSM photodetectors. A small dark current of ≈1 fA along with a high detectivity of 9.16 × 1011 Jones is achieved. The working principles and finite element analysis are presented to explain the origin of the self-driven property and its dependence on the degree of asymmetry.

Original languageEnglish
Article number1802954
JournalAdvanced Functional Materials
Issue number45
Publication statusPublished - 7 Nov 2018


  • 2D materials
  • low dark current
  • metal–semiconductor–metal
  • self-driven photodetectors

ASJC Scopus subject areas

  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics


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