Infrared Proximity Sensors Based on Photo‐Induced Tunneling in van der Waals Integration. (28th May 2021)

• Record Type: Journal Article
• Authors: Kim, Young Rae; Phan, Thanh Luan; Cho, Kye Whan; Kang, Won Tae; Kim, Kunnyun; Lee, Young Hee; Yu, Woo Jong
• Is Part Of: Advanced functional materials. Volume 31:Number 31(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-28
• Subjects: 2D materials -- infrared -- photodetectors -- sensors -- tunneling; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202100966
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Infrared (IR) detectors based on photo‐induced tunneling in van der Waals heterostructures (vdWHs) of graphene/h‐BN/graphene or MoS2 /h‐BN/graphene exhibit extremely low dark currents owing to a large electron barrier. However, a lack of tunneling barrier materials except for h‐BN for 2D vdWHs limits their further enhancement. In this study, a broadband detection is reported with high sensitivity and fast photoresponse of IR proximity sensor by a vdW integration (2D‐3D) of graphene or MoS2, with NiO/Ni as the IR absorber and hole selective transport layer/counter electrode. The low Schottky barrier height of the reported junctions suppresses dark current with a high detectivity ≈ 10 14 Jones and generates a photocurrent by transporting photo‐excited carriers through a low hole barrier at a wide wavelength. Two types of integrated IR proximity sensor applications are developed: a passive sensor (MoS2 /NiO/Ni) for the near‐IR (NIR) range and an active sensor (Gr/NiO/Ni) for the mid‐IR (MIR) range. The former shows a broadband photoresponse to reflect the NIR, while the latter absorbs human body irradiation (2–16 µm wavelength) with a fast photoresponse of 3.5 s (rise time) and 1.8 s (fall time). The fabricated sensors utilize low power, broadband detection, high sensitivity, fast photoresponse, and large‐scale area at room temperature. Abstract : A lack of tunneling barrier materials except for h‐BN for 2D van der Waals heterostructures detectors limits their further enhancement. Herein, a broadband detection is reported with high sensitivity and fast photoresponse of an infrared proximity sensor by a vdW integration (2D‐3D) of graphene or MoS2, with NiO/Ni as the infrared absorber and hole selective transport layer/counter electrode.