Evaluation of model and dispersion parameters and their effects on the formation of constant-phase elements in equivalent circuits

AbstractThe Au/Pd/Ti–SiO2-(n) GaAs properties have been analyzed via impedance spectroscopy (IS), as well as DLTS and ICTS, to identify the origin of electron processes responsible for existence of constant phase elements (CPE) in an equivalent circuits of that structure. We showed that CPEs connected in series with resistance represents the electron processes associated with deep levels in GaAs and/or interface states at SiO2-(n) GaAs interface, depending on the value of n of CPE parameter. CPE with n close to 1 characterize the electron processes associated with EL2 deep level, and CPE with n = 0.5–0.65 the complex electron processes associated with EL3 deep level and interface states together. We stated that constant phase elements in equivalent circuits of MIS-GaAs structures with large frequency dispersion of electrical characteristics can be the result of more than one electron process.

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A Connection Between Anomalous Poisson–Nernst–Planck Model and Equivalent Circuits with Constant Phase Elements

The Journal of Physical Chemistry C ◽

10.1021/jp4063725 ◽

2013 ◽

Vol 117 (45) ◽

pp. 23685-23690 ◽

Cited By ~ 27

Author(s):

E. K. Lenzi ◽

J. L. de Paula ◽

F. R. G. B. Silva ◽

L. R. Evangelista

Keyword(s):

Equivalent Circuits ◽

Constant Phase Elements

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Application of Composite Distributed Electrodes in Cardiographic Sensors

Micro and Nanosystems ◽

10.2174/1876402913666210126145742 ◽

2021 ◽

Vol 13 ◽

Author(s):

Nikolai F. Uvarov ◽

Boris B. Bokhonov ◽

Artem S. Ulihin ◽

Alexander I. Titkov ◽

Yuriy M. Yukhin ◽

...

Keyword(s):

Wide Frequency Range ◽

Equivalent Model ◽

Equivalent Circuits ◽

Electrode Impedance ◽

Shape Distortion ◽

Distributed Parameters ◽

Real Change ◽

Electrode Interface ◽

Double Time ◽

Constant Phase Elements

Background: An analysis of equivalent circuits used to interpret the impedance of bio-electrode for electrocardiography shows that the best description is achieved using a double-time constant model of the skin-electrode interface. However, for the measurements it is necessary to use equipment with high input impedance, which leads to the loss of information about the real change in the bio-potential. Objective: The aim of the study is to comprehensively investigate and select the equivalent model that are used to interpret the impedance of a composite bioelectrode with distributed parameters. Method: We used theoretical and experimental research methods. Results: It is proposed for measuring bio-potential to use Ag/AgI/Al2O3 electrodes with distributed parameters. Such electrodes are characterized by a higher contact area and their impedance is described in terms of equivalent circuits with constant phase elements (CPE). It was shown that the electrode impedance is well described over a wide frequency range by an equivalent circuit typical for distributed electrodes including two CPE elements. Conclusion: It is experimentally shown that the distributed Ag/AgI/Al2O3 electrode has at least 6 times smaller polarization contribution than a commercial Ag/AgCl cardiographic electrode. It may enable more accurate measurements of bio-potentials providing less pulse shape distortion caused by polarization of electrochemical biosensors.

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