Elucidating the photoresponse of ultrathin MoS2 field-effect transistors by scanning photocurrent microscopy

Abstract

The mechanisms underlying the intrinsic photoresponse of few-layer (FL) molybdenum disulphide (MoS2) field-effect transistors are investigated via scanning photocurrent microscopy. We attribute the locally enhanced photocurrent to band-bending assisted separation of photoexcited carriers at the MoS2/Au interface. The wavelength-dependent photocurrents of few layer MoS2 transistors qualitatively follow the optical absorption spectra of MoS2, providing direct evidence of interband photoexcitation. Time and spectrally resolved photocurrent measurements at varying external electric fields and carrier concentrations establish that drift-diffusion currents dominate photothermoelectric currents in devices under bias.

4 figure letter + supporting information. Journal of Physical Chemistry Letters (2013)

References in corpus (11)

• Two Dimensional Atomic Crystals
• Anomalous Lattice Vibrations of Single and Few-Layer MoS2
• Valley polarization in MoS2 monolayers by optical pumping
• Single-Layer MoS2 Phototransistors
• Integrated Circuits Based on Bilayer MoS2 Transistors
• Channel Length Scaling of MoS2 MOSFETs
• Large and tunable photo-thermoelectric effect in single-layer MoS2
• Photoconductivity of biased graphene
• Electron-hole transport and photovoltaic effect in gated MoS2 Schottky junctions
• Mechanical and Electronic Properties of MoS${}_2$ Nanoribbons and Their Defects
• Band-Like Transport in High Mobility Unencapsulated Single-Layer MoS2 Transistors

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• Microscopic Origin of the Valley Hall Effect in Transition Metal Dichalcogenides Revealed by Wavelength Dependent Mapping
• MoS${}_2$-on-paper optoelectronics: drawing photodetectors with van der Waals semiconductors beyond graphite
• Layer Dependent Interfacial Transport and Optoelectrical Properties of MoS2 on Ultra-flat Metals
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• Local photodoping in monolayer MoS2
• Lithography-free electrical transport measurements on 2D materials by direct microprobing
• Efficiency of band edge optical transitions of 2D monolayer materials: A high-throughput computational study