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Published on: November 16, 2018
High-Performance Self-Powered Gr/MoS2/WSe2 Heterojunction Photodetector Based on Asymmetric Van Der Waals Contacts
Hedong Yao1, Yinan Zhang1,2, Heng Liu2
1National Key Laboratory of Semiconductor Laser, Changchun University of Science and Technology, Changchun130022, People's Republic of China.
ACS Applied Materials & Interfaces
|August 13, 2026
Summary
This study presents a novel graphene/molybdenum disulfide/tungsten diselenide (Gr/MoS2/WSe2) heterojunction photodetector. The device achieves high performance in self-powered operation due to optimized asymmetric contacts and built-in electric fields.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Optoelectronics
Background:
- Transition metal dichalcogenide heterostructures are promising for self-powered photodetectors.
- Schottky barriers at semiconductor/metal interfaces impede carrier transport.
- Reducing these barriers or using built-in electric fields is crucial for device enhancement.
Purpose of the Study:
- To construct a self-powered Gr/MoS2/WSe2 heterojunction photodetector with asymmetric van der Waals (vdW) contacts.
- To improve carrier transport and device performance by addressing interface barriers.
- To explore the potential of this heterojunction for advanced optoelectronic applications.
Main Methods:
- Fabrication of a Gr/MoS2/WSe2 heterojunction using asymmetric vdW contacts.
- Introduction of graphene as a transparent electrode to enhance MoS2/Au interface characteristics.
- Characterization of device performance under self-powered conditions, including responsivity, on/off ratio, and response times.
Main Results:
- The device exhibits fast rise/fall times (22/58 μs) and a very low dark current (5.54 × 10-13 A).
- Achieved a high responsivity of 367 mA/W and an on/off ratio exceeding 10^6 under self-powered operation.
- Demonstrated photodetection across visible and near-infrared spectrum, with applications in imaging and optical communication.
Conclusions:
- Asymmetric vdW contacts and built-in electric fields effectively regulate carriers in Gr/MoS2/WSe2 heterojunctions.
- The developed photodetector shows excellent performance for self-powered optoelectronic applications.
- This work highlights the potential of vdW heterostructures for next-generation photodetectors.
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