Fast multicolor photodetectors based on graphene-contacted p-GaSe/n-InSe van der Waals heterostructures

Abstract

The integration of different two-dimensional materials within a multilayer van der Waals (vdW) heterostructure offers a promising technology for realizing high performance opto-electronic devices such as photodetectors and light sources1-3. Transition metal dichalcogenides, e.g. MoS2 and WSe2, have been employed as the optically-active layer in recently developed heterojunctions. However, MoS2 and WSe2 become direct band gap semiconductors only in mono- or bilayer form4,5. In contrast, the metal monochalcogenides InSe and GaSe retain a direct bandgap over a wide range of layer thicknesses from bulk crystals down to exfoliated flakes only a few atomic monolayers thick6,7. Here we report on vdW heterojunction diodes based on InSe and GaSe: the type II band alignment between the two materials and their distinctive spectral response, combined with the low electrical resistance of transparent graphene electrodes, enable effective separation and extraction of photoexcited carriers from the heterostructure even when no external voltage is applied. Our devices are fast (< 10 μs), self-driven photodetectors with multicolor photoresponse ranging from the ultraviolet to the near-infrared and have the potential to accelerate the exploitation of two-dimensional vdW crystals by creating new routes to miniaturized optoelectronics beyond present technologies.

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Cited by in corpus (16)

• Atomically thin p-n junctions based on two-dimensional materials
• Near-direct bandgap $WS{e}_2$/$Re{S}_2$ type-II pn heterojunction for enhanced ultrafast photodetection and high-performance photovoltaics
• Solution-processed GaSe nanoflake-based films for photoelectrochemical water splitting and photoelectrochemical-type photodetectors
• Large and tunable magnetoresistance in van der Waals Ferromagnet/Semiconductor junctions
• Multilayer InSe-Te van der Waals heterostructures with ultrahigh rectification ratio and ultrasensitive photoresponse
• Enhanced optical Kerr nonlinearity of graphene/Si hybrid waveguide
• The optical properties of few-layer InSe
• Highly Sensitive MoS2 Photodetectors with Graphene Contacts
• Spin-orbit coupling, optical transitions, and spin pumping in mono- and few-layer InSe
• Evidence of Direct Electronic Band Gap in two-dimensional van der Waals Indium Selenide crystals
• Review of Nanolayered Post-transition Metal Monochalcogenides: Synthesis, Properties, and Applications
• Interfacial charge transfer and gate induced hysteresis in monochalcogenide InSe/GaSe heterostructures
• Van Der Waals Heteroepitaxy of GaSe and InSe, Quantum Wells and Superlattices
• Two-dimensional InSe/WS${}_2$ heterostructure with enhanced optoelectronic performance in the visible region
• Van der Waals interlayer potential of graphitic structures: from Lennard-Jones to Kolmogorov-Crespy and Lebedeva models
• Thickness and twist angle dependent interlayer excitons in metal monochalcogenide heterostructures