Work

Elucidating the Photoresponse of Ultrathin MoS 2 Field-Effect Transistors by Scanning Photocurrent Microscopy

Year: 2013

Type: article

Abstract: The mechanisms underlying the intrinsic photoresponse of few-layer (FL) molybdenum disulfide (MoS 2 ) 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 MoS 2 /Au interface. The wavelength-dependent photocurrents of FL MoS 2 transistors qualitatively follow the optical absorption spectra of MoS 2, 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.

Source: The Journal of Physical Chemistry Letters

DOI: 10.1021/jz401199x

Authors: Chung-Chiang Wu, Deep Jariwala, Vinod K. Sangwan, Tobin J. Marks, Mark C. Hersam, Lincoln J. Lauhon

Institution: Northwestern University

Language: English

Topic: 2D Materials and Applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green