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141 Analytical model of high-frequency noise spectrum in Schottky-barrier diodes
Author(s): P. Shiktorov, E. Starikov, V. Gruzinskis (Affiliation: Semicond. Phys. Inst., Vilnius, Lithuania), L. Reggiani, L. Varani, J.C. Vaissiere
Journal: IEEE Electron Device Lett. (USA), vol.26, no.1, p.2-4 (Jan. 2005)
Publisher: IEEE, USA
Language: English
ISSN: 0741-3106, Full text
Document type: Journal article
Abstract: We propose an analytical model for the highfrequencynoise of Schottky-barrier diodes (SBD). The highfrequencyspectrum is shown to be governed by collectivemotions of carriers in the neutral region of the SBD caused bythe self-consistent electric field. The model is validated bycomparison with Monte Carlo simulations of GaAs SBDsoperating from barrier-limited to flatband conditions (8 refs.)
Inspec No.: 8250013
142 Development of nuclear radiation detectors with energy resolution capability based on CdTe-n+-GaAs heterojunction diodes
Author(s): M. Niraula, K. Yasuda, K. Uchida, Y. Nakanishi, T. Mabuchi, Y. Agata (Affiliation: Graduate Sch. of Eng., Nagoya Inst. of Technol., Japan), K. Suzuki
Journal: IEEE Electron Device Lett. (USA), vol.26, no.1, p.8-10 (Jan. 2005)
Publisher: IEEE, USA
Language: English
ISSN: 0741-3106, Full text
Document type: Journal article
Abstract: CdTe-n+-GaAs heterojunction diodes for roomtemperaturenuclear radiation detectors have been developedand demonstrated. The heterojunction diode was fabricated bygrowing a thin n-type CdTe buffer layer followed by theundoped p-like CdTe layer of about a 100 ìm thickness on then+-GaAs substrates using metal-organic vapor phase epitaxy.The diode detectors exhibited good rectification property andhad the reverse leakage currents of a few ìA/cm2 at 40 Vbias. The detector clearly demonstrated its energy resolutioncapability by resolving the 59.54 keV gamma peak from the241Am radioisotope during the radiation detection test (12 refs.)
Inspec No.: 8250015
143 PECVD diamond-based high performance power diodes
Author(s): Y. Gurbuz (Affiliation: Fac. of Eng. & Natural Sci., Sabanci Univ., Istanbul, Turkey), Weng Poo Kang, J.L. Davidson, D.V. Kerns, Q. Zhou
Journal: IEEE Trans. Power Electron. (USA), vol.20, no.1, p.1-10 (Jan. 2005)
Publisher: IEEE, USA
Language: English
ISSN: 0885-8993, Full text
Document type: Journal article
Abstract: In this study, we have designed, fabricated,characterized, and analyzed plasma-enhanced chemicalvapor deposition (PECVD) diamond-based Schottky diodes forhigh power electronics applications. We have elaborated fourcritical issues in the synthetic-diamond semiconductortechnology: 1) growth, 2) doping, 3) Schottky contact, and 4)different device structures in order to achieve betterperformance parameters. We have obtained 500 V ofbreakdown voltage on one device and 100 A/cm2 of currentdensity on another device, optimized for different applications.These values are among the highest reported with thepolycrystalline diamond-based devices. We have utilizeddifferent fabrication techniques for the growth of PECVDdiamond,different metals as a Schottky contact on diamondfilm and also optimized structural parameters such asdiamond film thickness and doping concentration in order toachieve a high-performance power diodes. Analysis of thecurrent conduction mechanisms of these devices in this studyrevealed a space-charge-limited current conductionmechanism in the forward bias region while thermionic fieldemission controlled current conduction mechanism in thereverse bias region. Performance parameters such as forwardvoltage drop, barrier height, and current density wereanalyzed as a function of temperature and type of metalSchottky contacts (32 refs.)
Inspec No.: 8250576
144 Wave propagation in RTD-based cellular neural networks
Author(s): Cheng-Hsiung Hsu, Suh-Yuh Yang (Affiliation: Dept. of Math., Nat. Central Univ., Chung-li, Taiwan)
Journal: J. Differ. Equ. (USA), vol.204, no.2, p.339-79 (20 Sept. 2004)
Publisher: Academic Press, USA
Language: English
ISSN: 0022-0396, Full text
Document type: Journal article
Abstract: This work investigates the existence of monotonictraveling wave and standing wave solutions of RTD-basedcellular neural networks in the one-dimensional integer latticeZ1. For nonzero wave speed c, applying the monotoneiteration method with the aid of real roots of the correspondingcharacteristic function of the profile equation, we can partitionthe parameter space (ã,ä)-plane into four regions such that allthe admissible monotonic traveling wave solutions connectingtwo neighboring equilibria can be classified completely. Forthe case of c=0, a discrete version of the monotone iterationscheme is established for proving the existence of monotonicstanding wave solutions. Furthermore, if ã or ä is zero then theprofile equation for the standing waves can be viewed as anone-dimensional iteration map and we then prove themultiplicity results of monotonic standing waves by using thetechniques of dynamical systems for maps. Some numericalresults of the monotone iteration scheme for traveling wavesolutions are also presented (21 refs.)
Inspec No.: 8250265
145 The effects of the time-dependent on the characteristic parameters of polypyrrole/p-type Si/Al diode
Author(s): M. Saglam, D. Korucu, A. Turut (Affiliation: Dept. of Phys., Ataturk Univ., Erzurum, Turkey)
Journal: Polymer (UK), vol.45, no.21, p.7335-40 (29 Sept. 2004)
Publisher: Elsevier, UK
Language: English
ISSN: 0032-3861, Full text
Document type: Journal article
Abstract: A detailed study of the effects of the time-dependentor aging on the characteristic parameters of polypyrrole/p-typeSi/Al structure has been presented. The polypyrrole film hasbeen formed on a p-type Si substrate by means of ananodization process. The polypyrrole/p-Si contact hasdemonstrated clearly rectifying behavior by the current-voltagecurves studied at room temperature. The current-voltage (I-V)curves of the diode have been measured immediately, 7, 15,30, 60 and 90 days after fabrication of the polypyrrole/p-Sicontact. It has been seen that the characteristics parameterssuch as barrier height, ideality factor and series resistance ofpolypyrrole/p-type Si/Al structure have changed withincreasing ageing time. Furthermore, the density distribution ofinterface states of the device was obtained from the forwardbias I-V characteristics. The fact that the diode shows nonidealI-V behavior with increasing ageing time may beascribed to a slow replacement of the initial doping agent byoxygen and this process certainly plays a role in the aging ofthe diode (21 refs.)
Inspec No.: 8252661
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