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Article
Self-Driven Metal-Semiconductor-Metal Wse2 Photodetector with Asymmetric Contact Geometries
Electrical and Computer Engineering
  • Changjian Zhou
  • Salahuddin Raju
  • Bin Li
  • Mansun Chan
  • Yang Chai
  • Cary Y. Yang, Santa Clara University
Document Type
Article
Publication Date
9-20-2018
Publisher
John Wiley & Sons, Inc.
Abstract

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.

Citation Information
C. Zhou, S. Raju, B. Li, M. Chan, Y. Chai, and C.Y. Yang, “Self-Driven Metal-Semiconductor-Metal Wse2 Photodetector with Asymmetric Contact Geometries,” Advanced Functional Materials 28, 1802954 (8 pp) (2018).