Contact resistance

About: Contact resistance is a research topic. Over the lifetime, 15262 publications have been published within this topic receiving 232144 citations. The topic is also known as: electrical contact resistance & ECR.

Impact of Contact on the Operation and Performance of Back-Gated Monolayer MoS2 Field-Effect-Transistors.

Abstract: Metal contacts to atomically thin two-dimensional (2D) crystal based FETs play a decisive role in determining their operation and performance. However, the effects of contacts on the switching behavior, field-effect mobility, and current saturation of monolayer MoS2 FETs have not been well explored and, hence, is the focus of this work. The dependence of contact resistance on the drain current is revealed by four-terminal-measurements. Without high-κ dielectric boosting, an electron mobility of 44 cm2/(V·s) has been achieved in a monolayer MoS2 FET on SiO2 substrate at room temperature. Velocity saturation is identified as the main mechanism responsible for the current saturation in back-gated monolayer MoS2 FETs at relatively higher carrier densities. Furthermore, for the first time, electron saturation velocity of monolayer MoS2 is extracted at high-field condition.

Electromagnetic wave absorption properties of a carbon nanotube modified by a tetrapyridinoporphyrazine interface layer

Abstract: Thinner absorbents with high dielectric loss usually cannot meet the requirement of impedance match, and multi-layer absorbents with excellent performance usually cannot be thin. Thus, it is a challenge to balance strong dielectric loss and impedance matching. An impedance matching interface layer can provide abundant interfaces, which are highly desirable for enhancing electromagnetic absorbing capability and decreasing surface reflection. In this study, cobalt tetrapyridinoporphyrazine (CoTAP) was assembled on the surface of multi-walled carbon nanotubes (MWCNTs) as a shell via a coordination bond; this produced a heterostructure and enhanced interfacial polarization loss at the hetero-interface. The impedance matching characteristic of the CoTAP–CNT hybrid can be optimized by the CoTAP shell with an intermediate conductivity. Contact resistance between CNTs can be increased via insulation owing to the CoTAP shell, which decreases surface EM reflection. When the CNT content of the CoTAP–CNTs hybrid is 30 wt% and the thickness of the absorber is 2.1 mm, the minimum value of the reflection coefficient and the corresponding frequency are −54.7 dB and 9.8 GHz, respectively. The combination of CNTs and the intermediate dielectric loss CoTAP in a core–shell hybrid can overcome the contradiction of strong dielectric loss and impedance matching of traditional materials; this can be considered as an effective route for designing high-performance EM absorbing materials.

Simple hydrothermal synthesis of very-long and thin silver nanowires and their application in high quality transparent electrodes

Abstract: Solution-processed silver nanowire (AgNW) random mesh is a strong contender to commercial indium tin oxide (ITO); however, its performance is limited due to large contact resistance between nanowires and post-processing treatments. As an alternative, long nanowires can decrease the number of contact points and contact resistance. Here, a simple modified hydrothermal method for the synthesis of very-long silver nanowires (AgNWs) and their use in a high quality transparent conducting electrode without post-processing has been developed. Well dispersed very-long and thin silver nanowires are synthesized by using glucose as a reducing agent and silver chloride as a silver source. The lengths of the wires are in the range of 200 to 500 μm with an average diameter of 45–65 nm. To the best of our knowledge, this is the first report on long nanowires having a thin diameter with greater than 200 microns length. As compared to other transparent conductors and nanowire networks, this AgNW network shows a higher percolative figure of merit (FoM, Π) with low haze. A flexible touch screen using the AgNW network is also demonstrated which has shown good performance even on a bendable surface.

Intermetallic compounds at aluminum-to-copper electrical interfaces: effect of temperature and electric current

Abstract: The effects of intermetallic compounds on the electrical and mechanical properties of bimetallic friction welded Al-Cu joints was studied. The formation and growth of intermetallic compounds was studied in the temperature ranges 200-525/spl deg/C. In addition, the effect of electrical current on the morphology and kinetics of formation of intermetallic compounds of bimetallic friction welded aluminum-copper joints was studied in the temperature ranges 200-500/spl deg/C that was realized by heating Al-Cu joints with an ac current of different intensities (400-1000 A). The contact resistance was found to increase linearly with the thickness of the intermetallics. The presence of an electrical field greatly accelerates the kinetics of formation of intermetallic phases and alters significantly their morphology. The growth kinetics of intermetallic phases under the influence of electrical current is much higher than that under diffusion annealing in furnace. >