High Detectivity and Transparent Few-Layer MoS2/Glassy-Graphene Heterostructure Photodetectors

Abstract

Layered van der Waals heterostructures have attracted considerable attention recently, due to their unique properties both inherited from individual two-dimensional (2D) components and imparted from their interactions. Here, a novel few-layer MoS₂/glassy-graphene heterostructure, synthesized by a layer-by-layer transfer technique, and its application as transparent photodetectors are reported for the first time. Instead of a traditional Schottky junction, coherent ohmic contact is formed at the interface between the MoS₂ and the glassy-graphene nanosheets. The device exhibits pronounced wavelength selectivity as illuminated by monochromatic lights. A responsivity of 12.3 mA W⁻¹ and detectivity of 1.8 × 10¹⁰ Jones are obtained from the photodetector under 532 nm light illumination. Density functional theory calculations reveal the impact of specific carbon atomic arrangement in the glassy-graphene on the electronic band structure. It is demonstrated that the band alignment of the layered heterostructures can be manipulated by lattice engineering of 2D nanosheets to enhance optoelectronic performance.

Transparent photodetectors based on a novel few-layer MoS₂/glassy-graphene heterostructure which exhibit high detectivity and distinct wavelength selectivity, are reported. It is demonstrated that ohmic contact is formed at the heterojunction. Density functional theory calculations reveal the band alignment of the layered heterostructures can be manipulated by lattice engineering of 2D nanosheets to enhance optoelectronic performance.

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