The device level modulation of carrier transport in a 2D WSe2 field effect transistor via a plasma treatment.

Tungsten diselenide (WSe2) has received significant attention because it shows the pristine ambipolar property arising from the Fermi level located near the midgap and can be converted to uni-polar form. In this study, we observe the formation of tungsten oxide (WOx) on the WSe2 surface after oxygen plasma treatment and show that the p-type WOx dopes WSe2. In our devices that underwent plasma treatment, it was interesting to find a strong correlation between the changes in the work function of WSe2 and a gold electrode, and the channel and contact resistances. The channel resistance changes very sensitively at a rate of 64 meV per dec with the increase in the WSe2 channel work function, which is close to the thermal limit; this indicates the defect-free oxidized WSe2 channel. The carrier transport in the oxidized WSe2 FET is shown to change to a high performance p-type device with greatly reduced channel and contact resistances with the increase in the plasma oxidation time.

[1]  K. Tsukagoshi,et al.  Layer-by-Layer Oxidation Induced Electronic Properties in Transition-Metal Dichalcogenides , 2018, The Journal of Physical Chemistry C.

[2]  B. Grévin,et al.  Multimodal Kelvin Probe Force Microscopy Investigations of a Photovoltaic WSe2/MoS2 Type-II Interface. , 2018, ACS Applied Materials and Interfaces.

[3]  Beng Kang Tay,et al.  Electronic Properties of Bulk and Monolayer TMDs: Theoretical Study Within DFT Framework (GVJ‐2e Method) , 2017 .

[4]  Weichao Wang,et al.  In situ visualization and detection of surface potential variation of mono and multilayer MoS2 under different humidities using Kelvin probe force microscopy , 2017, Nanotechnology.

[5]  Claudia Felser,et al.  Topological Quantum Phase Transition and Superconductivity Induced by Pressure in the Bismuth Tellurohalide BiTeI , 2016, Advanced materials.

[6]  Lukmaan A. Bawazer,et al.  Combinatorial Evolution of Biomimetic Magnetite Nanoparticles , 2017 .

[7]  Hyochul Kim,et al.  Large Work Function Modulation of Monolayer MoS2 by Ambient Gases. , 2016, ACS nano.

[8]  Eric Pop,et al.  Improved Contacts to MoS2 Transistors by Ultra-High Vacuum Metal Deposition. , 2016, Nano letters.

[9]  Kazuhito Tsukagoshi,et al.  Self-Limiting Oxides on WSe2 as Controlled Surface Acceptors and Low-Resistance Hole Contacts. , 2016, Nano letters.

[10]  Renaud Demadrille,et al.  High-Resolution Kelvin Probe Force Microscopy Imaging of Interface Dipoles and Photogenerated Charges in Organic Donor-Acceptor Photovoltaic Blends. , 2016, ACS nano.

[11]  Du Xiang,et al.  Surface transfer doping induced effective modulation on ambipolar characteristics of few-layer black phosphorus , 2015, Nature Communications.

[12]  Kazuhito Tsukagoshi,et al.  Self-limiting layer-by-layer oxidation of atomically thin WSe2. , 2015, Nano letters.

[13]  F. Xia,et al.  Two-dimensional material nanophotonics , 2014, Nature Photonics.

[14]  Yi-sheng Liu,et al.  Air stable p-doping of WSe2 by covalent functionalization. , 2014, ACS nano.

[15]  Y. Ping,et al.  Optimizing the Band Edges of Tungsten Trioxide for Water Oxidation: A First-Principles Study , 2014 .

[16]  A. Kahn,et al.  Transition Metal Oxides for Organic Electronics: Energetics, Device Physics and Applications , 2012, Advanced materials.

[17]  A. Javey,et al.  High-performance single layered WSe₂ p-FETs with chemically doped contacts. , 2012, Nano letters.

[18]  J. Maultzsch,et al.  Graphene on Si(111)7×7 , 2012, Nanotechnology.

[19]  Franco Cacialli,et al.  Time dependence and freezing-in of the electrode oxygen plasma-induced work function enhancement in polymer semiconductor heterostructures , 2011 .

[20]  Zhenghong Lu,et al.  Oxidized Gold Thin Films: An Effective Material for High‐Performance Flexible Organic Optoelectronics , 2009, Advanced materials.

[21]  V. Dravid,et al.  Direct evidence of oxidized gold on supported gold catalysts. , 2005, The journal of physical chemistry. B.

[22]  Andre K. Geim,et al.  Electric Field Effect in Atomically Thin Carbon Films , 2004, Science.

[23]  E. Sacher,et al.  Surface Chemistry of Gold Nanoparticles Produced by Laser Ablation in Aqueous Media , 2004 .