Photophysics and Electronic Structure of Lateral Graphene/MoS2 and Metal/MoS2 Junctions
- Pennsylvania State Univ., University Park, PA (United States)
- Pennsylvania State Univ., University Park, PA (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Univ. of Wurzburg (Germany)
- Technische Univ. Munchen, Garching (Germany)
- Technische Univ. Munchen, Garching (Germany); The Barcelona Inst. of Science and Technology, Castelldefels (Spain)
- Carnegie Mellon Univ., Pittsburgh, PA (United States)
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies (CINT)
- Technische Univ. Munchen, Garching (Germany); Univ. of Munster (Germany)
Integration of semiconducting transition metal dichalcogenides (TMDs) into functional optoelectronic circuitries requires an understanding of the charge transfer across the interface between the TMD and the contacting material. In this work, we use spatially resolved photocurrent microscopy to demonstrate electronic uniformity at the epitaxial graphene/molybdenum disulfide (EG/MoS2) interface. A 10× larger photocurrent is extracted at the EG/MoS2 interface when compared to the metal (Ti/Au)/MoS2 interface. This is supported by semi-local density functional theory (DFT), which predicts the Schottky barrier at the EG/MoS2 interface to be ~2× lower than that at Ti/MoS2. We provide a direct visualization of a 2D material Schottky barrier through combination of angle-resolved photoemission spectroscopy with spatial resolution selected to be ~300 nm (nano-ARPES) and DFT calculations. A bending of ~500 meV over a length scale of ~2-3 μm in the valence band maximum of MoS2 is observed via nano-ARPES. We explicate a correlation between experimental demonstration and theoretical predictions of barriers at graphene/TMD interfaces. Spatially resolved photocurrent mapping allows for directly visualizing the uniformity of built-in electric fields at heterostructure interfaces, providing a guide for microscopic engineering of charge transport across heterointerfaces. This simple probe-based technique also speaks directly to the 2D synthesis community to elucidate electronic uniformity at domain boundaries alongside morphological uniformity over large areas.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Center for Integrated Nanotechnologies (CINT)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Science Foundation (NSF); Swiss National Science Foundation (SNF); Alexander von Humboldt Foundation; Federal Ministry of Education and Research (BMBF); Saudi Aramco; Defense Advanced Research Projects Agency (DARPA); German Research Foundation (DFG); USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC02-05CH11231; P300P2-171221; EFMA 1433378; EFMA 1433307; DMREF-1729338; NA0003525
- OSTI ID:
- 1762198
- Journal Information:
- ACS Nano, Vol. 14, Issue 12; ISSN 1936-0851
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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