2021, PdSe2/MoSe2 vertical heterojunction for self-powered photodetector with high performance, Nano Research

PdSe2/MoSe2 vertical heterojunction for self-powered photodetector with high performance. Nano Research

Abstract:

Van der Waals’ two-dimensional (2D) materials heterostructure engineering offers an effective strategy for the design of multifunctional and high-performance optoelectronic devices. However, 2D heterostructure photodetectors with a photoconductive effect tend to suffer from high driving source-drain voltages and significant dark noise currents. Here, a self-powered photodetector with high performance was fabricated based on vertically stacked graphene (Gr)/ PdSe2/MoSe2/Gr heterojunctions through a dry transfer method. The fabricated device displays current rectification characteristics in darkness (on/off ratio >103) and superior photovoltaic behaviors under illumination. In addition, benefitting from the strong built-in field, the Gr/PdSe2/MoSe2/Gr heterojunction photodetector is able to respond to a broad spectrum from visible to near-infrared (NIR) with a remarkable responsivity of 651 mA W-1, a high specific detectivity of 5.29×1011 Jones and a fast response speed of 41.7/62.5μs. Moreover, an enhanced responsivity of 1.16A/W has been obtained by a reverse voltage (-1V) and further evaluation on image recognition has also demonstrated the great application potential of the Gr/PdSe2/MoSe2/Gr heterojunction photodetector. The findings are expected to bring new opportunities for the development of highly sensitive, high-speed and energy-efficient photodetectors for comprehensive applications.

Keywords: 2D material, heterostructure, PdSe2, self-powered photodetector, high performance 

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