Schottky barrier

About: Schottky barrier is a research topic. Over the lifetime, 22570 publications have been published within this topic receiving 427746 citations. The topic is also known as: Schottky barrier junction.

An Atomically Layered InSe Avalanche Photodetector

Abstract: Atomically thin photodetectors based on 2D materials have attracted great interest due to their potential as highly energy-efficient integrated devices. However, photoinduced carrier generation in these media is relatively poor due to low optical absorption, limiting device performance. Current methods for overcoming this problem, such as reducing contact resistances or back gating, tend to increase dark current and suffer slow response times. Here, we realize the avalanche effect in a 2D material-based photodetector and show that avalanche multiplication can greatly enhance the device response of an ultrathin InSe-based photodetector. This is achieved by exploiting the large Schottky barrier formed between InSe and Al electrodes, enabling the application of a large bias voltage. Plasmonic enhancement of the photosensitivity, achieved by patterning arrays of Al nanodisks onto the InSe layer, further improves device efficiency. With an external quantum efficiency approaching 866%, a dark current in the pic...

Ligand-exchange assisted formation of Au/TiO2 Schottky contact for visible-light photocatalysis.

Abstract: Plasmonic noble metal nanoparticles have emerged as a promising material in sensitizing wide-bandgap semiconductors for visible-light photocatalysis. Conventional methods in constructing such heterocatalysts suffer from either poor control over the size of the metal nanoparticles or inefficient charge transfer through the metal/semiconductor interface, which limit their photocatalytic activity. To solve this problem, in this work we construct Au/TiO2 photocatalysts by depositing presynthesized colloidal Au nanoparticles with well-controlled sizes to TiO2 nanocrystals and then removing capping ligands on the Au surface through a delicately designed ligand-exchange method, which leads to close Au/TiO2 Schottky contact after a mild annealing process. Benefiting from this unique synthesis strategy, the obtained photocatalysts show superior activity to conventionally prepared photocatalysts in dye decomposition and water-reduction hydrogen production under visible-light illumination. This study not only opens ...

On the physics of metal-semiconductor interfaces

Abstract: Almost all metal-semiconductor or Schottky contacts exhibit rectifying behaviour which is caused by a depletion layer on the semiconductor side of the interface. The electronic properties of a Schottky diode are characterised by its barrier height which is the energy difference between the top of the valence band of the semiconductor and the Fermi level at the interface. The physical mechanism primarily determining barrier height is provided by the decay of the metal's electron wavefunctions into the semiconductor in the energy range between the top of the valence band and the Fermi level where the metal conduction band overlaps the semiconductor band gap. These wavefunction tails are described as the continuum of metal-induced gap states (MIGS) which are derived from the virtual gap states of the complex semiconductor band structure.

Silicon-Nanowire Transistors with Intruded Nickel-Silicide Contacts

Abstract: Schottky barrier field effect transistors based on individual catalytically-grown and undoped Si-nanowires (NW) have been fabricated and characterized with respect to their gate lengths. The gate length was shortened by the axial, self-aligned formation of nickel-silicide source and drain segments along the NW. The transistors with 10−30 nm NW diameters displayed p-type behaviour, sustained current densities of up to 0.5 MA/cm2, and exhibited on/off current ratios of up to 107. The on-currents were limited and kept constant by the Schottky contacts for gate lengths below 1 μm, and decreased exponentially for gate lengths exceeding 1 μm.

Tuning On–Off Current Ratio and Field-Effect Mobility in a MoS2–Graphene Heterostructure via Schottky Barrier Modulation

Abstract: Field-effect transistor (FET) devices composed of a MoS2–graphene heterostructure can combine the advantages of high carrier mobility in graphene with the permanent band gap of MoS2 for digital applications. Herein, we investigate the electron transfer, photoluminescence, and gate-controlled carrier transport in such a heterostructure. We show that the junction is a Schottky barrier, whose height can be artificially controlled by gating or doping graphene. When the applied gate voltage (or the doping level) is zero, the photoexcited electron–hole pairs in monolayer MoS2 can be split by the heterojunction, significantly reducing the photoluminescence. By applying negative gate voltage (or p-doping) in graphene, the interlayer impedance formed between MoS2 and graphene exhibits an 100-fold increase. For the first time, we show that the gate-controlled interlayer Schottky impedance can be utilized to modulate carrier transport in graphene, significantly depleting the hole transport, but preserving the electr...