Issues and Challenges in Vapor-Deposited Top Metal Contacts for Molecule-Based Electronic Devices

2011 ◽  
pp. 239-273 ◽  
Author(s):  
Masato M. Maitani ◽  
David L. Allara
Keyword(s):  
Electronic Devices ◽  
Metal Contacts

scholarly journals Efficient Ohmic contacts and built-in atomic sublayer protection in MoSi2N4 and WSi2N4 monolayers

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Qianqian Wang ◽  
Liemao Cao ◽  
Shi-Jun Liang ◽  
Weikang Wu ◽  
Guangzhao Wang ◽  
...  
Keyword(s):  
Energy Efficient ◽  
High Performance ◽  
Ohmic Contacts ◽  
Schottky Barrier Height ◽  
Electronic Devices ◽  
Metal Contacts ◽  
Fermi Level Pinning ◽  
2D Semiconductors ◽  
Semiconductor Electronic ◽  
Wide Range

AbstractMetal contacts to two-dimensional (2D) semiconductors are often plagued by the strong Fermi level pinning (FLP) effect which reduces the tunability of the Schottky barrier height (SBH) and degrades the performance of 2D semiconductor devices. Here, we show that MoSi2N4 and WSi2N4 monolayers—an emerging 2D semiconductor family with exceptional physical properties—exhibit strongly suppressed FLP and wide-range tunable SBH. An exceptionally large SBH slope parameter of S ≈ 0.7 is obtained which outperforms the vast majority of other 2D semiconductors. Such intriguing behavior arises from the septuple-layered morphology of MoSi2N4 and WSi2N4 monolayers in which the semiconducting electronic states are protected by the outlying Si–N sublayer. We identify Ti, Sc, and Ni as highly efficient Ohmic contacts to MoSi2N4 and WSi2N4 with zero interface tunneling barrier. Our findings reveal the potential of MoSi2N4 and WSi2N4 as a practical platform for designing high-performance and energy-efficient 2D semiconductor electronic devices.

scholarly journals 1,4-Dithiolbenzene, 1,4-dimethanediolbenzene and 4-thioacetylbiphenyl molecular systems: electronic devices with possible applications in molecular electronics

RSC Advances ◽  
2020 ◽  
Vol 10 (53) ◽  
pp. 32127-32136
Author(s):  
J. H. Ojeda ◽  
Lina K. Piracón Muñoz ◽  
Julian A. Guerra Pinzón ◽  
Jovanny A. Gómez Castaño
Keyword(s):  
Transport Properties ◽  
Molecular Electronics ◽  
Electronic Transport ◽  
Theoretical Study ◽  
Electronic Devices ◽  
Metal Contacts ◽  
Molecular Systems ◽  
Electronic Transport Properties

A theoretical study of the electronic transport properties of the 1,4-dithiolbenzene, 1,4-dimethanediolbenzene and 4-thioacetylbiphenyl molecules coupled to two metal contacts is carried out.

scholarly journals Exfoliation and Characterization of V2Se9 Atomic Crystals

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 737 ◽  
Author(s):  
Bum Kim ◽  
Byung Jeong ◽  
Seungbae OH ◽  
Sudong Chae ◽  
Kyung Choi ◽  
...  
Keyword(s):  
Solid State ◽  
Mass Production ◽  
Electronic Devices ◽  
Metal Contacts ◽  
Si Substrate ◽  
Kelvin Probe ◽  
One Dimensional ◽  
Kelvin Probe Microscopy ◽  
Microscopy Analysis

Mass production of one-dimensional, V2Se9 crystals, was successfully synthesized using the solid-state reaction of vanadium and selenium. Through the mechanical exfoliation method, the bulk V2Se9 crystal was easily separated to nanoribbon structure and we have confirmed that as-grown V2Se9 crystals consist of innumerable single V2Se9 chains linked by van der Waals interaction. The exfoliated V2Se9 flakes can be controlled thickness by the repeated-peeling method. In addition, atomic thick nanoribbon structure of V2Se9 was also obtained on a 300 nm SiO2/Si substrate. Scanning Kelvin probe microscopy analysis was used to explore the variation of work function depending on the thickness of V2Se9 flakes. We believe that these observations will be of great help in selecting suitable metal contacts for V2Se9 and that a V2Se9 crystal is expected to have an important role in future nano-electronic devices.

Ultra-High Performance Organic Thermoelectric Generators through Interfacial Doping Gradients

2020 ◽  
Author(s):  
I. Petsagkourakis ◽  
S. Riera-Galindo ◽  
Tero-Petri Ruoko ◽  
Xenofon Strakosas ◽  
Eleni Pavlopoulou ◽  
...  
Keyword(s):  
High Performance ◽  
Electronic Devices ◽  
Fine Tuning ◽  
Organic Layer ◽  
Ambient Atmosphere ◽  
Metal Contacts ◽  
Organic Electronic Devices ◽  
Output Performance ◽  
Metal Polymer ◽  
Interfacial Energetics

Abstract The interfacial energetics are known to play a crucial role in organic electronic devices. However, their effects in organic thermoelectrics remain to be elucidated. In this work we optimize the output power density of an organic thermoelectric generator (OTEG) at ambient atmosphere to record high values, by varying the work function of the metal contacts. We find that the effect is linked to extended gradients of doping states, which are induced by humidity and reside inside the organic layer oriented perpendicular to the metal contacts. The thermovoltage, arising from this contact phenomenon alone, reaches a magnitude similar to that of the Seebeck voltage of the conducting polymer itself, thereby providing a major contribution to the resulting thermoelectric performance. With this work, we put a new emphasis on the importance of the metal-polymer interface in thermoelectrics. The overall output performance can be greatly improved by fine-tuning the interfacial energetics, which then provides an attractive complementing route for enhancing the performance of OTEGs.

Quantum Transport in Nanotube-Based Structures

2001 ◽  
Vol 706 ◽  
Author(s):  
M. Buongiorno Nardelli ◽  
J.-L. Fattebert ◽  
J. Bernholc
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Contact Resistance ◽  
Transport Properties ◽  
Quantum Transport ◽  
State Of The Art ◽  
Electronic Devices ◽  
Quantum Calculations ◽  
Metal Contacts ◽  
Electromechanical Systems

AbstractUsing state of the art quantum calculations, we have studied the electronic and transport properties of a variety of nanotube-based structures relevant for the design of nanoscale electronic devices. We have investigated the conductance of carbon nanotubes under mechanica distortions such as bending, defects and tube-tube contacts, and analyzed the behavior of carbon nanotube-metal contacts with the aim of explaining the anomalously large contact resistance observed in nanotube devices. Our results provide a clear interpretation of recent experimenta findings and suggest avenues for the use of carbon nanotubes in electromechanical systems.

The study of interfacial reactions of nickel thin films on GaAs

1983 ◽  
Vol 41 ◽  
pp. 156-157
Author(s):  
L.J. Chen ◽  
Y.F. Hsieh
Keyword(s):  
Thin Films ◽  
Integrated Circuits ◽  
Interfacial Reactions ◽  
Metal Contacts ◽  
Nickel Thin Films ◽  
Thin Foils ◽  
The Status ◽  
Si Doped ◽  
Electron Microscopes

One measure of the maturity of a device technology is the ease and reliability of applying contact metallurgy. Compared to metal contact of silicon, the status of GaAs metallization is still at its primitive stage. With the advent of GaAs MESFET and integrated circuits, very stringent requirements were placed on their metal contacts. During the past few years, extensive researches have been conducted in the area of Au-Ge-Ni in order to lower contact resistances and improve uniformity. In this paper, we report the results of TEM study of interfacial reactions between Ni and GaAs as part of the attempt to understand the role of nickel in Au-Ge-Ni contact of GaAs.N-type, Si-doped, (001) oriented GaAs wafers, 15 mil in thickness, were grown by gradient-freeze method. Nickel thin films, 300Å in thickness, were e-gun deposited on GaAs wafers. The samples were then annealed in dry N2 in a 3-zone diffusion furnace at temperatures 200°C - 600°C for 5-180 minutes. Thin foils for TEM examinations were prepared by chemical polishing from the GaA.s side. TEM investigations were performed with JE0L- 100B and JE0L-200CX electron microscopes.

Atom-probe analysis of the solid-liquid interface

1995 ◽  
Vol 53 ◽  
pp. 676-677
Author(s):  
J.A. Panitz
Keyword(s):  
Molecular Level ◽  
Selective Adsorption ◽  
Electronic Devices ◽  
Atom Probe ◽  
Chemical Agent ◽  
Hostile Environment ◽  
Solid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Chemically Selective

The first few atomic layers of a solid can form a barrier between its interior and an often hostile environment. Although adsorption at the vacuum-solid interface has been studied in great detail, little is known about adsorption at the liquid-solid interface. Adsorption at a liquid-solid interface is of intrinsic interest, and is of technological importance because it provides a way to coat a surface with monolayer or multilayer structures. A pinhole free monolayer (with a reasonable dielectric constant) could lead to the development of nanoscale capacitors with unique characteristics and lithographic resists that surpass the resolution of their conventional counterparts. Chemically selective adsorption is of particular interest because it can be used to passivate a surface from external modification or change the wear and the lubrication properties of a surface to reflect new and useful properties. Immunochemical adsorption could be used to fabricate novel molecular electronic devices or to construct small, “smart”, unobtrusive sensors with the potential to detect a wide variety of preselected species at the molecular level. These might include a particular carcinogen in the environment, a specific type of explosive, a chemical agent, a virus, or even a tumor in the human body.

The morphologies and electrical properties of indium contacts on (100) cadmium telluride surfaces

1992 ◽  
Vol 50 (2) ◽  
pp. 1422-1423
Author(s):  
A.M. Letsoalo ◽  
M.E. Lee ◽  
E.O. de Neijs
Keyword(s):  
Electrical Properties ◽  
Cadmium Telluride ◽  
Methanol Solution ◽  
Electrical Characteristics ◽  
Metal Contacts ◽  
Deposition Technique ◽  
Interfacial Layers ◽  
Semiconductor Contacts ◽  
Grown Single Crystal ◽  
Diamond Abrasive

Semiconductor devices require metal contacts for efficient collection of electrical charge. The physics of these metal/semiconductor contacts assumes perfect, abrupt and continuous interfaces between the layers. However, in practice these layers are neither continuous nor abrupt due to poor nucleation conditions and the formation of interfacial layers. The effects of layer thickness, deposition rate and substrate stoichiometry have been previously reported. In this work we will compare the effects of a single deposition technique and multiple depositions on the morphology of indium layers grown on (100) CdTe substrates. The electrical characteristics and specific resistivities of the indium contacts were measured, and their relationships with indium layer morphologies were established.Semi-insulating (100) CdTe samples were cut from Bridgman grown single crystal ingots. The surface of the as-cut slices were mechanically polished using 5μm, 3μm, 1μm and 0,25μm diamond abrasive respectively. This was followed by two minutes immersion in a 5% bromine-methanol solution.

Study of dislocation loops in Arsenic-Rich as-grown GaAs

1987 ◽  
Vol 45 ◽  
pp. 350-351
Author(s):  
Byung-Teak Lee
Keyword(s):  
Point Defects ◽  
Electronic Devices ◽  
Arsenic Concentration ◽  
Stoichiometric Compound ◽  
Dislocation Loops ◽  
Gaas Crystal ◽  
Ion Milling ◽  
Transmission Electron ◽  
Arsenic Source ◽  
High Arsenic

Grown-in dislocations in GaAs have been a major obstacle in utilizing this material for the potential electronic devices. Although it has been proposed in many reports that supersaturation of point defects can generate dislocation loops in growing crystals and can be a main formation mechanism of grown-in dislocations, there are very few reports on either the observation or the structural analysis of the stoichiometry-generated loops. In this work, dislocation loops in an arsenic-rich GaAs crystal have been studied by transmission electron microscopy.The single crystal with high arsenic concentration was grown using the Horizontal Bridgman method. The arsenic source temperature during the crystal growth was about 630°C whereas 617±1°C is normally believed to be optimum one to grow a stoichiometric compound. Samples with various orientations were prepared either by chemical thinning or ion milling and examined in both a JEOL JEM 200CX and a Siemens Elmiskop 102.

Sign in / Sign up

Export Citation Format

Share Document