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.

van der Waals Heterostructure of Phosphorene and Graphene: Tuning the Schottky Barrier and Doping by Electrostatic Gating

Abstract: In this Letter, we study the structural and electronic properties of single-layer and bilayer phosphorene with graphene. We show that both the properties of graphene and phosphorene are preserved in the composed heterostructure. We also show that via the application of a perpendicular electric field, it is possible to tune the position of the band structure of phosphorene with respect to that of graphene. This leads to control of the Schottky barrier height and doping of phosphorene, which are important features in the design of new devices based on van der Waals heterostructures.

Enhancing sensitivity of a single ZnO micro-/nanowire photodetector by piezo-phototronic effect

Abstract: We demonstrate the piezoelectric effect on the responsivity of a metalsemiconductormetal ZnO micro-/nanowire photodetector. The responsivity of the photodetector is respectively enhanced by 530%, 190%, 9%, and 15% upon 4.1 pW, 120.0 pW, 4.1 nW, and 180.4 nW UV light illumination onto the wire by introducing a0.36% compressive strain in the wire, which effectively tuned the Schottky barrier height at the contact by the produced local piezopotential. After a systematic study on the Schottky barrier height change with tuning of the strain and the excitation light intensity, an in-depth understanding is provided about the physical mechanism of the coupling of piezoelectric, optical, and semiconducting properties. Our results show that the piezo-phototronic effect can enhance the detection sensitivity more than 5-fold for pW levels of light detection.

Ag3PO4/Ti3C2 MXene interface materials as a Schottky catalyst with enhanced photocatalytic activities and anti-photocorrosion performance

Abstract: The high carrier recombination rate and serious photocorrosion of Ag3PO4 greatly restrict its photocatalytic application. Here, we fabricated an Ag3PO4/Ti3C2 Schottky catalyst and found that Ti3C2 can greatly enhanced the catalytic activity and stability of Ag3PO4. This arises from: (i) the abundant surface hydrophilic functional groups of Ti3C2 construct strong interfacial contact with Ag3PO4, which facilitate the separation of carriers; (ii) the strong redox reactivity of surface Ti sites promote multiple electron reduction reactions to induce more OH production; and (iii) a Schottky junction formed at Ag3PO4-Ti3C2 interface timely transfer electrons to Ti3C2 surface by built-in electric field, inhibiting the photocossion of Ag3PO4 caused by photogeneration electrons. Consequently, Ag3PO4/Ti3C2 exhibited excellent photocatalytic activity and stability for the degradation of organic pollutants. Especially, the apparent rate constant of 2,4-Dinitrophenol degradation with Ag3PO4/Ti3C2 was 2.5 times that of Ag3PO4/RGO and 10 times that of Ag3PO4. The photocatalytic performance of Ag3PO4/Ti3C2 toward tetracycline hydrochloride still maintained 68.4% after 8 cycles, while Ag3PO4/RGO and Ag3PO4 only maintained 36.2% and 7.8%, respectively. Furthermore, the efficient photoreduction of Cr6+ using AgI/Ti3C2 further illustrated an enormous potential in coupling Ti3C2 with other photosensitivity semiconductor to improve their catalytic activity and stability.

The Concept of Fermi Level Pinning at Semiconductor/Liquid Junctions. Consequences for Energy Conversion Efficiency and Selection of Useful Solution Redox Couples in Solar Devices

Abstract: Fermi level pinning refers to a situation where the band bending in a semiconductor contacting a metal is essentially independent of the metal even for large variation in the work function of the metal. It was found that a similar situation sometimes results for a semiconductor contacting liquid electrolyte solutions containing redox couples having very different electrochemical potentials. Recently, workers in the field of semiconductor photoelectrochemistry have emphasized a limiting case of the model of the semiconductor/liquid interface where the drop across the semiconductor depends on applied potential; at equilibrium with the solution, the band bending is generally regarded as varying with changes in the solution potential by virtue of changes in the redox couple or simply changing the ratio of oxidized and reduced material. Fermi level pinning results in semiconductor/liquid interfaces which can be viewed as analogous to a Schottky barrier photocell in series with an electrochemical cell in that the extent to which a given redox process can be driven uphill is independent of the potential of the redox couple.n-GaAs, p-GaAs, p-GaAs, and p-Si are semiconductors that exhibit Fermi level pinning in liquid electrolyte solutions (CH/sub 3/CN/(n-Bu/sub 4/N)ClO/sub 4/) of redox reagents. Fermi level pinning has the disadvantagemore » in practical terms of limiting photovoltage in optical energy conversion applications, but such a phenomenon allows the use of a very wide range of solution couples. Since Fermi level pinning results from surface states, changes in the surface brought about by deliberate surface chemistry may change the surface states and hence the photovoltage in solid-state and liquid-junction solar devices.« less

Electrical properties of grain boundaries in polycrystalline compound semiconductors

Abstract: In polycrystalline semiconductors the trapping of charge at the grain boundaries has a decisive influence on the electrical transport properties through the formation of electrostatic potential barriers. By proper materials processing many interesting device applications can be realised, which exploit the electrical activity of these interfaces. In this review, the authors describe both the origin and the consequences of the charge capturing at grain boundaries. Special emphasis is given to polycrystalline compound semiconductors, where they summarise the present knowledge on the interface microstructure and its electrical properties. The model of a double Schottky barrier is shown to provide a quantitative basis for understanding the wide range of electrical phenomena in this class of materials. The steady-state current-voltage characteristic becomes highly non-linear through the interplay between the applied bias and the occupation of the defect states at the interface and in the depletion regions. For large potential barriers, high doping levels and elevated bias, large electric fields build up in the depletion regions. This triggers minority carrier generation through impact ionisation by hot majority carriers and strongly enhances the non-linearities in the charge transport. The dynamic electrical properties are probed by AC admittance or pulse measurements and can be traced back to the finite relaxation times of the trapped electron and hole charges. Comparing the experimental results with the theoretical predictions allows one to obtain valuable information on the electronic grain boundary parameters. The relationship between the observed electrical properties and the electronic structure of the junctions is discussed in detail, with ZnO varistors providing the majority of the experimental data. First indications for a general picture of the grain boundary electronic structure appropriate for all compound semiconductors are presented.