Electrical Switching Phenomena Research Articles

A reversible electrical memory switching and its microscopic mechanism in amorphous (NCTA) 2Ni(DMIT) 2 thin films

A reversible and reproducible bistable electrical memory switching phenomenon was observed in an asymmetrical sandwich structure with coherent electrodeposited amorphous thin films between Al and indium tin oxide electrodes based on a new type of molecular semiconductor (NCTA) 2Ni(DMIT) 2. It can be achieved between a high-impedance OFF state and a low-impedance ON state simply by changing the polarity of an applied electric field across the device. The electrical memory switching process is described in detail, and a plausible microscopic switching mechanism is proposed based on the formation and deformation of mixed-valence semiconductor through electric field-induced solid-state redox reaction resulting from a negative fractional charge withdrawing and injecting process.

A study on the electrical switching mechanism in [TBA] x[Ni(dmid) 2] thin film materials by XPS

A study on the electrical switching mechanism in [TBA] x [Ni(dmid) 2] thin film materials, in which reproducible current-controlled bistable electrical switching and memory phenomena could be observed [1], by X-ray photoelectron spectroscopy (XPS) was reported. The effects of fabrication electrodes and preparation conditions of the sandwich structure devices on the switching behavior were presented as well.

Electrical switching and memory phenomena in the Ag-BDCP thin film

A novel organic materials 2,6-bis(2,2-bicyanovinyl)pyridine (BDCP) and its complex function thin films of Ag-BDCP were synthesized in our laboratory. Stable and reproducible electric bistable properties were observed in the Ag-BDCP thin films. The thin films were analyzed by high-resolution scanning electron microscopy, X-ray diffraction, ultraviolet-visible absorption and infrared transmission spectroscopy.

Ionized cluster beam deposition of , Ag-TCNQ thin films and electrical switching phenomena

The ionized cluster beam deposition of Ag-tetracyanoquinodimethane (TCNQ) and -TCNQ thin films is reported. These thin films were characterized by transmission electron microscopy and electron absorption spectroscopy. The microstructure of the thin films and the formation of a -TCNQ thin film were observed. Furthermore, the electrical properties of the thin films were measured and both films were able to exhibit electrical bistability. The conduction mechanism of the polymer thin films with Ag and is discussed.

Electrical Switching and Memory Phenomena in Electrodeposited [TBA]x[Ni(DMID)2] Thin Films

Abstract This paper reports reproducible bistable electrical switching and memory phenomena observed in a lamellar structure with an amorphous film of [TBA]x[Ni(DMID)2] between Pt and Al electrodes where the [TBA]x[Ni(DMID)2] is electrically deposited on a Pt substrate with galvanostatic conditions (TBA = tetrabutylammonium, DMID = 1,3-dithiole-2-one-4,5-dithiolate).The switching effect is insensitive to air, moisture, light, and the polarity of the applied potentials. The device is stable over a long period of time and has a lifetime of roughly 20 switching cycles. The current-voltage characteristics reveal an abrupt increase in impedance from 300Ω to about 100 kΩ at a field strength of about 2400 V/cm for a 10 μm film sample. Switching with high-power dissipation yields a high-impedance memory state which can be erased by the application of high voltage in either direction. The character of the switching from a low to a high impedance state in this organic charge transfer complex is in contrast to the o...

On the Electrical Switching Characteristics of the Bulk Metal Chalcogenide Glassy Semiconductor Cu0.10As0.40Se0.50 with a Double Point Contact Electrode System

The dc current-voltage characteristics of the metal chalcogenide glassy semiconductor Cu0.10As0.40Se0.50, using a double point contact electrode system, are obtained, showing nearly ohmic behavior. The electrical resistance obeys an Arrhenius-type dependence on the ambient temperature. Also, relationships between the applied voltage and the delay time, obtained by interrupting the process just before the electrical switching phenomenon takes place, and between the threshold voltage and the ambient temperature, are found and explained by a physical model based on the thermal breakdown theory. Finally, a phenomenological dependence of threshold voltage on the difference between the glass transition and ambient temperatures is also checked, obtaining excellent agreement for the experimental results.

Electrical switching and memory phenomena ino-tolidine DDQ under pressure

Abstract. Electrical switching has been observed in o-tolidine-DDQ at pressures of 7-66 GPa and Gelds $\sim3 X 10^5 V/m$ with $\sigma _{ON}/ \sigma _{OFF} \approx 10^3$ at a temperature of 300K. The switching is found to be of the memory type and the sample can be driven back to the low conducting state by applying ac pulses of sufficient magnitude but independent of frequency.

Switching characteristics of hydrogenated amorphous silicon/crystalline silicon heterojunction devices

A new structure of a three-terminal hydrogenated amorphous silicon/crystalline silicon (a-Si:H/c-Si) heterojunction switching device is successfully developed. The device can be controlled by a gate bias. The switching voltage, holding voltage, and switching current all increase with an increase of undoped a-Si:H thickness. The electrical characteristics and switching phenomena of this device are discussed.

On non-ohmic conduction and the threshold characteristics of a bulk-type switching device based on the chalcogenide glassy semiconductor As 0.40Se 0.30Te 0.30

The threshold characteristics of a switching device, based on a bulk semiconducting glass sample of composition As 0.40Se 0.30Te 0.30, have been examined. The experimental results are discussed in terms of the thermal breakdown model. The relationship between switching delay time and applied voltage is close to that predicted for the limiting case called impulse thermal breakdown. On the other hand, the dependence of threshold voltage on temperature correctly fits the one corresponding to steady-state thermal breakdown, confirming the fundamentally thermal nature of the electrical switching phenomenon. A non-ohmic process has been observed in the glass alloy under study (there are some signs of a space-charge limited current-type non-ohmic effect), although it does not play an important role in the switching effect. The weak field ohmic resistance-temperature characteristics are of the Arrhenius-type, an activation energy for the electrical conduction process of approximately 0.5 eV having been found. Lastly, the complete thermal balance equation has been numerically solved, and the results show good agreement with the experimental values.

Summary Abstract: Materials aspects of electrical switching phenomena in vertical polycrystalline silicon structures

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The temperature dependence of the electrical conductivity and switching phenomena in Cu2O single crystals

Optical transmission work had shown that three distinct types of Cu2O single crystals could be created by means of different annealing processes. We have now made mobility measurements and a series of current–voltage measurements over the ambient to 200 °C range. All types of crystals were subject to breakdown at sufficiently high electric fields and temperatures in accordance with a previously known mechanism. Two new switching effeets, one of which is optically induced, are shown to exist in the highest resistivity material.

Electrical switching and memory phenomena in Cu-TCNQ thin films

Stable and reproducible current-controlled bistable electrical switching has been observed in polycrystalline organic semiconducting films. The effect has been observed in a lamellar structure with a film of microcrystalline Cu-TCNQ between Cu and Al electrodes where the Cu-TCNQ is grown on a Cu substrate via a spontaneous electrolysis technique. The switching effect is insensitive to moisture and is observed over a large temperature range. The current-voltage characteristics reveal an abrupt decrease in impedance from 2 MΩ to less than 200 Ω at a field strength of 4×103 V/cm. The transition from a high- to low-impedance state occurs with delay and switching times of approximately 15 and 10 nsec, respectively. Switching with high-power dissipation yields a low-impedance memory state which can be erased by application of a short current pulse. An interpretation of this behavior is based on the bulk properties of the mixed valence semiconductor Cu-TCNQ.

Bipolar injection as a cause of electrical switching phenomena in thin organic films

An investigation of electrical conductance switching phenomena in thin organic films has been carried out. For thin films of p-quaterphenyl and tetracene grown in high vacuum the electrical conductance, dynamic capacitance and temperature patterns corresponding to the distribution of electrical current density have been measured. The measurements were carried out in vacuum as well as in humid air. It is suggested that previously reported switching phenomena are caused by field-induced bipolar injection of charge carriers.

Breakdown conduction in thin dielectric films: A bibliographical survey

Interest in the study of thin films has been greatly stimulated in recent years because of thier importance from the point of view of technological and industrial applications. A bibliographical survey limited mainly to breakdown conduction in thin films is presented here. To make the survey a more comprehensive and up-to-date source of information for the workers engaged in this field, the relevant references on some closely related fields, such as electrical conduction and switching phenomena, as well as on some other types of film systems and substances have also been included. The survey covers work published from 1960 onwards (few references appeared before then) and the references have been arranged in roughly chronological order together with the titles of the papers. In addition, a list of books, reviews and monographs has been given. The survey should also prove useful to assess the progress made by the scientific community in the field of breakdown conduction in thin dielectric films.

Switching in elemental amorphous semiconductors

Electrical switching phenomenon in amorphous thin films of boron, silicon and germanium is described. The effect of temperature and shelf-life on the threshold and sustaining voltages has been studied. The threshold voltage decreases with increasing temperature while the sustaining voltage is approximately independent of temperature. Both the voltages do not vary significantly with shelf-life. A memory effect is observed in amorphous silicon.

Electrical Switching Phenomena in Transition Metal Glasses under the Influence of High Electric Fields

AbstractA mechanism is proposed to account for the phenomena observed in many vitreous systems of field‐induced switching between two or more conducting states. Conduction in the high resistance state is assumed to involve electron hopping between non‐identical sites. The vitreous nature of the systems precludes extrinsic conduction, and the equilibrium number of intrinsic carriers is shown to be a function of the degree of inequality of site configurations, temperature, field strength, and dielectric constant. The carrier mobility is a function of averaged distance between sites, of temperature, and dielectric constant. Dc conduction and dipole production and orientation are shown to be interrelated processes. The consequent non‐linear dependence of polarization on field leads to a quasi‐ferroelectric reorganization of the structure at a critical field strength. The structural reorganization makes the site environments more nearly identical, and thereby delocalizes the excess electrons on one of the sites producing semi‐metallic conduction. Local energy dissipation by the turn‐off pulse raises the lattice temperature sufficiently to allow the structure to relax to its initial state. The quantitative implications of the theory are developed, and compared with measurements on some copper glasses.