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2. The external bias-dependent electric field at hole-injecting electrode/[alpha]-NPD junction and its relationship to Gaussian disordered interface statesBruno Cvikl, 2019, original scientific article Abstract: An alternative interpretation of two different sets of published temperature-dependent current-voltage a-NPD (i.e. N,N'-Di(1-naphthyl)-N,N'-diphenyl-(1,11-biphenyl)-4,4'-diamine) organic semiconductor data is presented. The measurements are described in terms of the hole drift current density expressed with two parameters: the electric field at the hole-injecting interface, Eint, and, ?max, the hole mobility determined by the measured current density at the maximum value of the externally applied electric field, Ea, in a given experiment. The former parameter, depending on the contact résistance, may be a function of Ea but the latter is Ea independent, The fixed value of Eint signifies the occurrence of the space charge limited current, SCLC, within the electrode/a-NPD structures and the contact is ohmic. Then, the calculated weak bias-dependent hole drift mobility, a function of Eint, equals the well%known exponential bias-dependent mobility, and saturates. The data not displaying SCLC characteristics are used for the calculation of Eint dependence on the applied field, Ea. It is shown that the quasi-ohmic contacts cause Eint to become a strong double-valued function of the externally applied electric field, Ea, described in terms of the distorted, inverted, high order parabola. The corresponding bias-dependent hole drift mobility is non-exponential and evolves on a considerably lower level than in SCLC cases. It is found that a sufficiently increased Ea alters the quasi-ohmic contact/a-NPD region into the ohmic one. A simple model of a thin, net hole charged, electrode/a-NPD interface enables the relationship between the deduced interfacial electric field, Eint, and the Ea dependent Gaussian width, as well as the energy shift of its peak along the negative binding energy is to be investigated. The currentvoltage method appears to be a helpful expedient for the investigation of the electric field at hole-injecting electrode/organic interfaces.
Keywords: electrode/organic electric field, contact affected hole mobility, organic interface disorder parameters
Published in DKUM: 22.12.2023; Views: 572; Downloads: 7
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3. Validation of electroanalytical method with antimony electrode for trace metal analysisAljaž Ramot, 2017, undergraduate thesis Abstract: The purpose of this thesis is to validate the electroanalytical method with an antimony electrode for trace metal analysis. The validation began with the determination of the limit of detection (LOD) and the limit of quantification (LOQ), proceeded with determining the method’s linearity and concluded with determination of accuracy and precision. The trace metal analysis was conducted via square-wave anodic stripping voltammetry (SWASV). Cyclic voltammetry (CV) was used to test the reversibility of the [Fe(CN)6] 3/[Fe(CN)6] 4 system. All the analyses were conducted in a 0.01 M HCl solution.
The LOD and LOQ were not possible to report with certainty, since the method has such a low LOD that the contamination with heavy metals, even in ultrapure acid, was too high. The method had a linear response at deposition potentials of 1.2 V, 1.1 V and 1.0 V vs. Ag/AgCl for Pb(II) and Cd(II) from 14.6 µg L 1 to 100.0 µg L 1. It has further been proven that the method is accurate and precise for all three deposition potentials at 15 µg L 1, 25 µg L 1, 30 µg L 1, 40 µg L 1 concentrations of analytes. The results have shown that the method is best used at a deposition potential of 1.1 V vs. Ag/AgCl.
Keywords: heavy metal analysis, trace analysis, antimony electrode, SWASV, voltammetry
Published in DKUM: 28.09.2017; Views: 1742; Downloads: 215
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4. A silver/silver sulphide selective electrode prepared by means of chemical treatments of silver wireDanilo Dobčnik, Igor Gros, Mitja Kolar, 1998, original scientific article Abstract: The preparation and usability of a sulphide ion selective electrode, prepared by means of chemical pretreatment of silver wire with an ammonium perdisulphate solution, and the sulphidization in an alkaline sulphide solution are described. The electrode is suitable for direct potentiometric measuring of sulphide in alkaline solutions of concentrations down to ▫$1 X 10^{-6} mol/L$▫. The 45 min required for each chemical treatment are enough for the preparation of the described electrode.
Keywords: analytical chemistry, ion selective electrode, preparation, silver wire, potentiometric measurements, sulphide ions
Published in DKUM: 17.08.2017; Views: 1403; Downloads: 127
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5. Determination of penicillamine by batch and flow-injection potentiometry with AgI-based sensorNjegomir Radić, Josipa Komljenović, Danilo Dobčnik, 2000, original scientific article Abstract: Potentiometric determination of penicillamine (pen) is described based on a batch experiment and flow-injection analysis (FIA) using a chemical sensor with AgI-based membrane. The membrane was prepared by pressing silver salts (AgI, Ag2S) and powdered Teflon. This membrane was incorporated in a multipurpose electrode body for batch measurements, and in a tabular flow-through sensor body for FIA measurements. For batch measurements, the equilibrium potentials recorded with continuous addition of standard penicillamine solution were considered in relation to ▫$lg(c_pen/mol L^-1)$▫. Linear response with slope of 60 mV was obtained in the concentration range from 2.5 x ▫$10^5$▫ mol ▫$L^1$▫ to 1.8 x ▫$10^-2$▫mol ▫$L-1$▫. In using the tubular sensor with a membrane of the same coposition for FIA measurements, the linear response with slope of 59 mV was recorded in the concentration range from 1 x ▫$10^4$▫ mol ▫$L^1$▫ to 1 x ▫$10^-1$▫ mol ▫$L^-1$▫. The response of the applied chemical sensor to penicillamine (designated also as RSH) is explained by the formation of sparingly soluble RSAg in the reaction solution and/or the exposed surface of the sensor. The solubility product ▫$K_s(RSAg)$▫ was determined using experimental values recorded both by batch measurements and by the continuous-flow experiment. The mean value obtained by different measurements and using a membrane of the same composition is ▫$K_s(RSAg)$▫ = (1.4+-0.1) x ▫$10^-20$▫ mol ▫$L-2$▫).
Keywords: analytical chemistry, batch potentiometry, flow-injection analysis, membrane electrode, tubular sensors, penicillamine
Published in DKUM: 05.07.2017; Views: 1316; Downloads: 90
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6. Integracija in analiza CAD/CAM sistema za izdelavo erodirnih elektrod v orodjarnahSimon Gašparič, 2013, undergraduate thesis Abstract: Diplomsko delo je nastalo kot plod praktičnega usposabljanja v Carreri Optyl Ormož in sicer z namenom, da bo služilo kot učno gradivo. Delo zajema analizo in delo s programskim paketom DelCAM in sicer DelCAM-PowerMill, ki služi za izdelavo programa za obdelavo izdelka in DelCAM- Electrode, ki služi za izdelavo erodirne elektrode. Podrobno sem opisal tudi potopno erozijo in delo na stroju za potopno erozijo Agie. Nadalje sem se posvetil tudi avtomatski izdelavi programa za potopno erozijo Agie, ki zajema postopek kako prenesemo datoteke iz računalnika na stroj in vse potrebe nastavitve in parametre, ki jih moramo upoštevati.
V zadnji točki diplomskega dela pa sem se posvetil še analizi med dvema programskima paketoma in sicer med Catio in DelCAMom. Primerjal sem ju v več različnih točkah in ugotovil, da je DelCAM v prednosti pred Catio in s tem upravičil nakup programskega paketa in mogoče tudi pripomogel k večji uporabi le tega.
Keywords: DelCAM, DelCAM-PowerMill, DelCAM-Electrode, potopna erozija, Catia
Published in DKUM: 17.10.2013; Views: 1688; Downloads: 231
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