Electrical conduction in niobium-niobium oxide-gold diodes

Schwartz, R. J.; Chiou, Y.L.; Thompson, H. W.

doi:10.1016/0040-6090(70)90065-9

Cited by 15 publications

(6 citation statements)

References 9 publications

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“…As shown in Fig. 6b , fitting the measured Poole-Frenkel activation energies yields a defect depth of 0.22 eV ± 0.01 eV, in agreement with the previously reported 0.22 eV activation energy for an oxygen vacancy in amorphous Nb 2 O 5 6 .…”

Section: Discussionsupporting

confidence: 90%

“…6a is activation of a deep defect state that contributes to the Poole-Frenkel current. Fitting the high temperature activation energy of the Poole-Frenkel Arrhenius plot yields a defect energy of 1.0 eV slightly lower than the reported 1.1 eV second ionization energy of an oxygen vacancy in Nb 2 O 5 6 . Emission from such a deep defect would be extremely slow, resulting in a negligible contribution to current.…”

Section: Discussionmentioning

confidence: 58%

“…Niobium Pentoxide (Nb2O5) has been studied as an insulating layer in MIM diodes since at least the 1960's 5 . These early studies on Nb -Anodized Nb2O5 -Au devices found rectification 5 and a Poole-Frenkel conduction mechanism 6 . The defect state enabling Poole-Frenkel conduction was found to lie between 0.22 -1.2 eV 5,6 below the conduction band edge and was attributed to oxygen vacancies 6 .…”

Section: Introductionmentioning

confidence: 99%

“…These early studies on Nb -Anodized Nb2O5 -Au devices found rectification 5 and a Poole-Frenkel conduction mechanism 6 . The defect state enabling Poole-Frenkel conduction was found to lie between 0.22 -1.2 eV 5,6 below the conduction band edge and was attributed to oxygen vacancies 6 . Additionally, it was found that upon dielectric breakdown these devices exhibited bistable switching in small conducting regions, similar to the NbO2 devices used in the 2013 neuristor demonstration 7 .…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Scalable Memdiodes Exhibiting Rectification and Hysteresis for Neuromorphic Computing

Shank

Tellekamp

Wahila

et al. 2018

Sci Rep

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Metal-Nb2O5−x-metal memdiodes exhibiting rectification, hysteresis, and capacitance are demonstrated for applications in neuromorphic circuitry. These devices do not require any post-fabrication treatments such as filament creation by electroforming that would impede circuit scalability. Instead these devices operate due to Poole-Frenkel defect controlled transport where the high defect density is inherent to the Nb2O5−x deposition rather than post-fabrication treatments. Temperature dependent measurements reveal that the dominant trap energy is 0.22 eV suggesting it results from the oxygen deficiencies in the amorphous Nb2O5−x. Rectification occurs due to a transition from thermionic emission to tunneling current and is present even in thick devices (>100 nm) due to charge trapping which controls the tunneling distance. The turn-on voltage is linearly proportional to the Schottky barrier height and, in contrast to traditional metal-insulator-metal diodes, is logarithmically proportional to the device thickness. Hysteresis in the I–V curve occurs due to the current limited filling of traps.

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Section: Discussionsupporting

confidence: 90%

Section: Discussionmentioning

confidence: 58%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Scalable Memdiodes Exhibiting Rectification and Hysteresis for Neuromorphic Computing

Shank

Tellekamp

Wahila

et al. 2018

Sci Rep

View full text Add to dashboard Cite

show abstract

“…In all devices, two trap levels are present; a deep trap level around ≈1.1 eV below the conduction band and a shallow trap level around ≈0.22 eV below the conduction band, which are attributed to the oxygen vacancies of the amorphous Nb 2 O 5‐ x layer. [ 23 ] The Pt/Ta 2 O 5 /Al 2 O 3‐ y /Ti (PTAT) device missing the Nb 2 O 5‐ x layer did not show memory operation, confirming that the Nb 2 O 5‐ x layer is responsible for the charge trapping. (see Figure S2b , Supporting Information, for the PTAT device I – V data).…”

Section: Resultsmentioning

confidence: 99%

Retention Secured Nonlinear and Self‐Rectifying Analog Charge Trap Memristor for Energy‐Efficient Neuromorphic Hardware

et al. 2022

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A memristive crossbar array (MCA) is an ideal platform for emerging memory and neuromorphic hardware due to its high bitwise density capability. A charge trap memristor (CTM) is an attractive candidate for the memristor cell of the MCA, because the embodied rectifying characteristic frees it from the sneak current issue. Although the potential of the CTM devices has been suggested, their practical viability needs to be further proved. Here, a Pt/Ta 2 O 5 /Nb 2 O 5‐ x /Al 2 O 3‐ y /Ti CTM stack exhibiting high retention and array‐level uniformity is proposed, allowing a highly reliable selector‐less MCA. It shows high self‐rectifying and nonlinear current‐voltage characteristics below 1 µA of programming current with a continuous analog switching behavior. Also, its retention is longer than 10 5 s at 150 °C, suggesting the device is highly stable for non‐volatile analog applications. A plausible band diagram model is proposed based on the electronic spectroscopy results and conduction mechanism analysis. The self‐rectifying and nonlinear characteristics allow reducing the on‐chip training energy consumption by 71% for the MNIST dataset training task with an optimized programming scheme.

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Threshold Modulative Artificial GABAergic Nociceptor

Kim,

Lee,

Jeon

et al. 2023

Advanced Materials

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Gamma‐aminobutyric acid (GABA) is a crucial inhibitory neurotransmitter of the central nervous system. It modifies the signal threshold of the nociceptor, allowing it to react to external stimuli in various circumstances. Thus, GABAergic behaviors are critical characteristics of the adaptive behavior in life. Here, we report a threshold‐modulative artificial GABAergic nociceptor for the first time at a Pt/Ti/Nb2O5–x/Al2O3‐y/Pt/Ti (top to bottom) of the double charge trapping structure. The Al2O3‐y layer contains deep defect states that function similarly to the GABA neurotransmitter in modulating the signal threshold. Meanwhile, the Nb2O5–x layer traps volatile charges and produces nociceptive behaviors. The combined dynamics of the two layers readily offer threshold‐modulative GABAergic nociceptive behaviors. Based on these GABAergic behaviors, we demonstrate a method of implementing hot‐ and cold‐sensitive thermoreceptors and show its potential applications in advanced sensory devices.This article is protected by copyright. All rights reserved

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Electrical conduction in niobium-niobium oxide-gold diodes

Cited by 15 publications

References 9 publications

Scalable Memdiodes Exhibiting Rectification and Hysteresis for Neuromorphic Computing

Scalable Memdiodes Exhibiting Rectification and Hysteresis for Neuromorphic Computing

Retention Secured Nonlinear and Self‐Rectifying Analog Charge Trap Memristor for Energy‐Efficient Neuromorphic Hardware

Threshold Modulative Artificial GABAergic Nociceptor

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