Carrier Injection and Scattering in Atomically Thin Chalcogenides

Abstract

Atomically thin two-dimensional chalcogenides such as MoS2 monolayers are structurally ideal channel materials for the ultimate atomic electronics. However, a heavy thickness dependence of electrical performance is shown in these ultrathin materials, and the device performance normally degrades while exhibiting a low carrier mobility as compared with corresponding bulks, constituting a main hurdle for application in electronics. In this brief review, we summarize our recent work on electrode/channel contacts and carrier scattering mechanisms to address the origins of this adverse thickness dependence. Extrinsically, the Schottky barrier height increases at the electrode/channel contact area in thin channels owing to bandgap expansion caused by quantum confinement, which hinders carrier injection and degrades device performance. Intrinsically, thin channels tend to suffer from intensified Coulomb impurity scattering, resulting from the reduced interaction distance between interfacial impurities and channel carriers. Both factors are responsible for the adverse dependence of carrier mobility on channel thickness in two-dimensional semiconductors.

18 pages, 8 figures. A brief review for the JPSJ SPECIAL TOPICS "Recent Progress in Science of Atomic Layers"

References in corpus (13)

• Two Dimensional Atomic Crystals
• Anomalous Lattice Vibrations of Single and Few-Layer MoS2
• Valley polarization in MoS2 monolayers by optical pumping
• Synthesis of Large-Area MoS2 Atomic Layers with Chemical Vapor Deposition
• Two-Dimensional Material Nanophotonics
• High Performance Single Layered WSe2 p-FETs with Chemically Doped Contacts
• Towards Intrinsic Charge Transport in Monolayer Molybdenum Disulfide by Defect and Interface Engineering
• Enhancement of Carrier Mobility in Semiconductor Nanostructures by Dielectric Engineering
• Towards barrier free contact to MoS2 using graphene electrodes
• Thickness Scaling Effect on Interfacial Barrier and Electrical Contact to Two-Dimensional MoS2 Layers
• Integrated complementary graphene inverter
• Complementary-like Graphene Logic Gates Controlled by Electrostatic Doping
• Enhanced Logic Performance with Semiconducting Bilayer Graphene Channels

Cited by in corpus (2)

• Charge transport and mobility engineering in two-dimensional transition metal chalcogenide semiconductors
• Coulomb screening and scattering in atomically thin transistors across dimensional crossover