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.

Bias stress instability in pentacene thin film transistors: Contact resistance change and channel threshold voltage shift

Abstract: Bias stress instability in top-contact pentacene thin film transistors was observed to be correlated not only to the channel but also to the metal/organic contact. The drain current decay under bias stress results from the combination of the contact resistance change and the threshold voltage shift in the channel. The contact resistance change is contact-metal dependent, though the corresponding channel threshold voltage shifts are similar. The results suggest that the time-dependent charge trapping into the deep trap states in both the contact and channel regions is responsible for the bias stress effect in organic thin film transistors.

Measuring local thermal conductivity in polycrystalline diamond with a high resolution photothermal microscope

Abstract: A photothermal microscope that provides micrometer lateral and submicrometer depth resolution was designed Thermal conductivity measurements with modulation frequencies up to 12 MHz on single grains in polycrystalline diamond demonstrate its lateral resolution power even for a highly conducting material Measured conductivities strongly depend on the averaged volume and values up to 2200 W/mK are found in the high frequency limit where the properties inside a grain are sampled The capability of the instrument to measure thermal parameters on thin films is demonstrated for gold films evaporated on quartz with a thickness ranging from 20 to 1500 nm Measurements reveal a strong thickness dependence for both thin film conductivity and the contact resistance between film and substrate Thermal conductivity decreases monotonically from 230 to 30 W/mK whereas the contact resistance rises from 2×10−7 to 8×10−6 m2K/W with decreasing film thickness

Corrosion Protection of Electrically Conductive Surfaces

Abstract: The basic function of the electrically conductive surface of electrical contacts is electrical conduction. The electrical conductivity of contact materials can be largely reduced by corrosion and in order to avoid corrosion, protective coatings must be used. Another phenomenon that leads to increasing contact resistance is fretting corrosion. Fretting corrosion is the degradation mechanism of surface material, which causes increasing contact resistance. Fretting corrosion occurs when there is a relative movement between electrical contacts with surfaces of ignoble metal. Avoiding fretting corrosion is therefore extremely challenging in electronic devices with pluggable electrical connections. Gold is one of the most commonly used noble plating materials for high performance electrical contacts because of its high corrosion resistance and its good and stable electrical behavior. The authors have investigated different ways to minimize the consumption of gold for electrical contacts and to improve the performance of gold plating. Other plating materials often used for corrosion protection of electrically conductive surfaces are tin, nickel, silver and palladium. This paper will deal with properties and new research results of different plating materials in addition to other means used for corrosion protection of electrically conductive surfaces and the testing of corrosion resistance of electrically conductive surfaces.

High‐Temperature Contact Formation on n‐Type Silicon: Basic Reactions and Contact Model for Seed‐Layer Contacts

Abstract: Contact formation on n-type silicon, especially using a high-temperature process, has been the subject of research for more than 40 years. After its application in microelectronics, n-type silicon is widely used in silicon solar cells as the emitter layer. The formation of a low ohmic contact grid using an industrially feasible process step is one of the key features required to improve the solar-cell efficiency. The contact materials, typically deposited in a printing step, have to fulfil several functions: opening the dielectric antireflection layer and forming an intimate metal-semiconductor contact with good mechanical adhesion and low specific contact resistance. As the used contact inks typically contain several functional materials, such as silver and a glass frit, the detailed contact formation is still not entirely understood. Therefore, the chemical reactions during the contact firing process have been studied in detail by thermogravimetric differential thermal analysis in combination with mass spectroscopy. Based on these studies, a contact ink has been developed, optimized and tested on silicon solar cells. In this paper, the mechanism of the etching process, the opening of a dielectric layer, the influence of different atmospheres and the impact of the glass-frit content are investigated. The observed microscopic contact structure, the resulting electrical solar-cell parameters and the studied reactions are combined to clarify the physics behind the high-temperature contact formation.

Ultrahigh sensitive MoTe2 phototransistors driven by carrier tunneling

Abstract: Transition metal dichalcogenides (TMDs) demonstrate great potential in electronic and optoelectronic applications. However, the device performance remains limited because of the poor metal contact. Herein, we fabricate a high-performance ultrathin MoTe2 phototransistor. By introducing an electron tunneling mechanism, electron injection from electrode to channel is strikingly enhanced. The electron mobility approaches 25.2 cm2 V−1 s−1, better than that of other back-gated MoTe2 FETs. Through electrical measurements at various temperatures, the electron tunneling mechanism is further confirmed. The MoTe2 phototransistor exhibits very high responsivity up to 2560 A/W which is higher than that of most other TMDs. This work may provide guidance to reduce the contact resistance at metal-semiconductor junction and pave a pathway to develop high-performance optoelectronic devices in the future.