scholarly journals The origin of constant phase element in equivalent circuit of MIS (n) GaAs structures

2020 ◽  
Vol 31 (21) ◽  
pp. 19106-19118
Author(s):  
Łukasz Drewniak ◽  
Stanisław Kochowski
Keyword(s):  
Impedance Spectroscopy ◽  
Constant Phase Element ◽  
Deep Level ◽  
Frequency Dispersion ◽  
Interface States ◽  
Equivalent Circuits ◽  
Electrical Characteristics ◽  
In Series ◽  
Constant Phase Elements ◽  
Large Frequency

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.

scholarly journals Correlation between Defects and Electrical Performances of Ion-Irradiated 4H-SiC p–n Junctions

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1966
Author(s):  
Domenico Pellegrino ◽  
Lucia Calcagno ◽  
Massimo Zimbone ◽  
Salvatore Di Franco ◽  
Antonella Sciuto
Keyword(s):  
Deep Level ◽  
Electrical Characterization ◽  
High Fluence ◽  
Defect States ◽  
Exponential Parameter ◽  
Current Voltage ◽  
Different Temperatures ◽  
In Series ◽  
Transient Spectroscopy ◽  
Fluence Range

In this study, 4H-SiC p–n junctions were irradiated with 700 keV He+ ions in the fluence range 1.0 × 1012 to 1.0 × 1015 ions/cm2. The effects of irradiation were investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements, while deep-level transient spectroscopy (DLTS) was used to study the traps introduced by irradiation defects. Modifications of the device’s electrical performances were observed after irradiation, and two fluence regimes were identified. In the low fluence range (≤1013 ions/cm2), I–V characteristics evidenced an increase in series resistance, which can be associated with the decrease in the dopant concentration, as also denoted by C–V measurements. In addition, the pre-exponential parameter of junction generation current increased with fluence due to the increase in point defect concentration. The main produced defect states were the Z1/2, RD1/2, and EH6/7 centers, whose concentrations increased with fluence. At high fluence (>1013 ions/cm2), I–V curves showed a strong decrease in the generation current, while DLTS evidenced a rearrangement of defects. The detailed electrical characterization of the p–n junction performed at different temperatures highlights the existence of conduction paths with peculiar electrical properties introduced by high fluence irradiation. The results suggest the formation of localized highly resistive regions (realized by agglomeration of point defects) in parallel with the main junction.

scholarly journals Electrical Impedance Spectroscopy as Electrical Biopsy for Monitoring Radiation Sequelae of Intestine in Rats

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Pei-Ju Chao ◽  
Eng-Yen Huang ◽  
Kuo-Sheng Cheng ◽  
Yu-Jie Huang
Keyword(s):  
Electrical Properties ◽  
Impedance Spectroscopy ◽  
Integrated Circuits ◽  
Electrical Impedance ◽  
Roc Analysis ◽  
Electrical Impedance Spectroscopy ◽  
Electrical Characteristics ◽  
Injury Score ◽  
Histological Changes ◽  
Radiation Sequelae

Electrical impedance is one of the most frequently used parameters for characterizing material properties. The resistive and capacitive characteristics of tissue may be revealed by electrical impedance spectroscopy (EIS) as electrical biopsy. This technique could be used to monitor the sequelae after irradiation. In this study, rat intestinal tissues after irradiation were assessed by EIS system based on commercially available integrated circuits. The EIS results were fitted to a resistor-capacitor circuit model to determine the electrical properties of the tissue. The variations in the electrical characteristics of the tissue were compared to radiation injury score (RIS) by morphological and histological findings. The electrical properties, based on receiver operation curve (ROC) analysis, strongly reflected the histological changes with excellent diagnosis performance. The results of this study suggest that electrical biopsy reflects histological changes after irradiation. This approach may significantly augment the evaluation of tissue after irradiation. It could provide rapid results for decision making in monitoring radiation sequelae prospectively.

scholarly journals Determination of Interface-State Distributions in Polymer-Based Metal-Insulator-Semiconductor Capacitors by Impedance Spectroscopy

2018 ◽  
Vol 8 (9) ◽  
pp. 1493 ◽  
Author(s):  
Hideyuki Hatta ◽  
Yuhi Miyagawa ◽  
Takashi Nagase ◽  
Takashi Kobayashi ◽  
Takashi Hamada ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Field Effect Transistors ◽  
Interface State ◽  
Interface States ◽  
Localized States ◽  
Electrical Performance ◽  
Metal Insulator ◽  
Metal Insulator Semiconductor ◽  
Gate Insulators ◽  
Mis Capacitors

Information on localized states at the interfaces of solution-processed organic semiconductors and polymer gate insulators is critical to the development of printable organic field-effect transistors (OFETs) with good electrical performance. This paper reports on the use of impedance spectroscopy to determine the energy distribution of the density of interface states in organic metal-insulator-semiconductor (MIS) capacitors based on poly(3-hexylthiophene) (P3HT) with three different polymer gate insulators, including polyimide, poly(4-vinylphenol), and poly(methylsilsesquioxane). The findings of the study indicate that the impedance characteristics of the P3HT MIS capacitors are strongly affected by patterning and thermal annealing of the organic semiconductor films. To extract the interface-state distributions from the conductance of the P3HT MIS capacitors, an equivalent circuit model with continuum trap states is used, which also takes the band-bending fluctuations into consideration. In addition, the relationship between the determined interface states and the electrical characteristics of P3HT-based OFETs is investigated.

Visualizing Impedance Spectroscopy Response for Interpretation of Collected Data

2021 ◽  
Vol 105 (1) ◽  
pp. 109-118
Author(s):  
Petr Vanysek
Keyword(s):  
Impedance Spectroscopy ◽  
Complex Permittivity ◽  
Electrical Impedance ◽  
Complex Modulus ◽  
Physical Reality ◽  
Standard Part ◽  
In Series ◽  
As If

Measurements and interpretation of electrical impedance in electrochemistry and in related studies has become recently fairly commonplace as both the hardware and the interpretation software are more and more standard part of electrochemical potentiostats. With the interpretation software it is possible to model the studied system in any conceivable way, even if the physical reality may not follow the chosen model. An example is given where a circuit consisting of a capacitor with resistors in series and parallel are evaluated as if the circuit were just a pure capacitor. The method of plotting the results as complex permittivity and complex modulus is also shown.

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