scholarly journals I-V measurements of Ge-Se-Sn chalcogenide glassy alloys

2015 ◽  
Vol 9 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Vandana Kumari ◽  
Anusaiya Kaswan ◽  
Dinesh Patidar ◽  
Narendra Saxena ◽  
Kananbala Sharma
Keyword(s):  
Elevated Temperatures ◽  
Low Voltage ◽  
Constant Load ◽  
Dc Conductivity ◽  
Voltage Range ◽  
Glassy Alloys ◽  
Current Voltage ◽  
Maximum Current ◽  
Current Voltage Characteristics ◽  
Minimum Resistance

Current-voltage characteristics and DC electrical conductivity were studied for Ge30-xSe70Snx (x = 8, 11, 14, 17 and 20) glassy thin pellets of diameter 12mm and thickness 1mm prepared under a constant load of 5 tons using a well-known melt quenching technique in bulk as a function of composition. The I-V characteristics were recorded at room temperature as well as elevated temperatures up to 300?C. The experimental data suggests that glass containing 20 at.% of Sn has the minimum resistance allowing maximum current through the sample as compared to other counterparts of the series. Therefore, DC conductivity is found to increase with increasing Sn concentration. Composition dependence of DC conductivity is discussed in terms of the bonding between Se and Sn. Plots between ln I and V1/2 provide linear relationship for both low and high voltage range. These results have been explained through the Pool-Frenkel mechanism. The I-V characteristics show ohmic behaviour in the low voltage range and this behaviour turns to non-ohmic from ohmic in the higher voltage range due to voltage induced temperature effects.

Study of Conduction Mechanism in Amorphous Se85-xTe15Bix Thin Films

2010 ◽  
Vol 303-304 ◽  
pp. 1-5 ◽  
Author(s):  
Ambika Sharma ◽  
P.B. Barman
Keyword(s):  
Thin Films ◽  
Conduction Mechanism ◽  
Low Voltage ◽  
Melt Quenching ◽  
Voltage Range ◽  
Glassy Alloys ◽  
Ohmic Behavior ◽  
Linear Behavior ◽  
Evaporation Technique ◽  
Minimum Resistance

Bulk samples of Se85-xTe15Bix (where x = 0, 1, 2, 3, 4, 5) glassy alloys are prepared by melt quenching technique. Thin films of the corresponding bulk samples are prepared by vacuum evaporation technique. I-V characteristics of Se85-xTe15Bix thin films are studied using Keithley 6487 picoammeter. Linear behavior of current has been observed at low voltage range and current is found to deviate from linearity i.e. tend towards non-Ohmic behavior in the higher voltage range. The value of resistance is also calculated in three different voltage ranges (0-90 V), (110-200 V) and (220-300 V) for the films under consideration. Maximum resistance has been observed for x = 1 and minimum resistance for x = 5. The conduction mechanism is discussed qualitatively and it is found to be of Poole Frenkel type for higher voltage range.

Metastable Variations of the Fill Factor in CIGS Thin Film Solar Cells

2009 ◽  
Vol 1165 ◽  
Author(s):  
Aleksander Urbaniak ◽  
Małgorzata Igalson
Keyword(s):  
Fill Factor ◽  
Elevated Temperatures ◽  
Reverse Voltage ◽  
Cell Behaviors ◽  
Cigs Thin Film ◽  
Current Voltage ◽  
Shallow Acceptors ◽  
Current Voltage Characteristics ◽  
Diode Behavior ◽  
Kinetics Of

AbstractWe investigate the origin of fill factor changes induced by reverse bias treatment. Evolution of current-voltage characteristics have been measured during application of reverse voltage bias. Two different cell behaviors have been identified. At elevated temperatures one kind of the devices strongly deteriorates and exhibit so called double diode behavior. On the other hand, in the same conditions another cells keep their fill factor almost constant. We correlate the fill factor changes with the kinetics of capacitance and show that although increased number of shallow acceptors itself cannot induce this severe FF deterioration, it may strongly influence position of the Fermi level at the heterointerface that in a presence of an electron barrier is crucial for the device behavior.

Mechanisms of negative differential resistance in glutamine-functionalized WS2 quantum dots

2021 ◽  
Author(s):  
Denice Feria ◽  
Sonia Sharma ◽  
Yu-Ting Chen ◽  
Zhi-Ying Weng ◽  
Kuo-Pin Chiu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Negative Differential Resistance ◽  
Electronic Devices ◽  
Transition Metal Dichalcogenides ◽  
Differential Resistance ◽  
Voltage Range ◽  
Current Voltage ◽  
Metal Dichalcogenides ◽  
Current Voltage Characteristics ◽  
Memory Applications

Abstract Understanding the mechanism of the negative differential resistance (NDR) in transition metal dichalcogenides is essential for fundamental science and the development of electronic devices. Here, the NDR of the current-voltage characteristics was observed based on the glutamine-functionalized WS2 quantum dots (QDs). The NDR effect can be adjusted by varying the applied voltage range, air pressure, surrounding gases, and relative humidity. A peak-to-valley current ratio as high as 6.3 has been achieved at room temperature. Carrier trapping induced by water molecules was suggested to be responsible for the mechanism of the NDR in the glutamine-functionalized WS2 QDs. Investigating the NDR of WS2 QDs may promote the development of memory applications and emerging devices.

High common-emitter current gains obtained by pnp GaN bipolar junction transistors

2001 ◽  
Vol 693 ◽  
Author(s):  
Kazuhide Kumakura ◽  
Toshiki Makimoto ◽  
Naoki Kobayashi
Keyword(s):  
Bipolar Junction Transistors ◽  
Base Thickness ◽  
Emitter Current ◽  
Base Current ◽  
Common Base ◽  
Current Voltage ◽  
Device Structures ◽  
Maximum Current ◽  
Current Voltage Characteristics ◽  
The Common

AbstractWe fabricated pnp GaN bipolar junction transistors and investigated their common-emitter and common-base current-voltage characteristics. The device structures were grown by metalorganic vapor phase epitaxy on a sapphire substrate. The base thickness was 0.12 μm and its electron concentration was estimated to be 3 × 1017 cm-3 from the common-emitter current-voltage characteristics and the base conductivity. The common-emitter current-voltage characteristics showed very low leak current. The maximum current gains at room temperature were 50 and 69 from the common-emitter and the common-base current-voltage characteristics, respectively.

Influence of Nickel Film Thicknesses on Dark Current-Voltage Characteristics of Silicon Solar Cells

2011 ◽  
Vol 694 ◽  
pp. 672-675
Author(s):  
Tao Li ◽  
Chun Lan Zhou ◽  
Zhen Gang Liu ◽  
Wen Jing Wang ◽  
Yang Song ◽  
...  
Keyword(s):  
Solar Cells ◽  
Dark Current ◽  
Nickel Silicide ◽  
Nickel Film ◽  
Silicon Solar Cells ◽  
Voltage Range ◽  
Voltage Curve ◽  
Current Voltage ◽  
Current Voltage Curve ◽  
Current Voltage Characteristics

In this paper, the dark current-voltage characteristics of p-n junction of silicon solar cells are analysed, with different nickel film thicknesses of 200nm, 400nm and 600nm. The formation of nickel silicide is obtained after the thermal annealing process for 1min, 5min and 10min. The dark current-voltage curves obtained by three kinds of annealing temperature as a function of time are achieved in experiment. The improvement of series resistance extracted from the dark current-voltage curve in the upper voltage range is observed. The influence of nickel film thicknesses on dark current-voltage characteristics of silicon solar cells is confirmed.

Analytical model of a-Si/c-Si Hit Solar Cell

1996 ◽  
Vol 420 ◽  
Author(s):  
J. Furlan ◽  
P. Popović ◽  
F. Smole ◽  
M. Topič
Keyword(s):  
Solar Cell ◽  
Order Effects ◽  
Solar Cell Performance ◽  
Voltage Range ◽  
Closed Form Solutions ◽  
Current Voltage ◽  
Cell Current ◽  
Current Voltage Characteristics ◽  
Recombination Current ◽  
Analytical Expressions

AbstractUsing suitable simplifying approximations inside the particular regions of a p-i a-Si/n c-Si heterojunction solar cell, the analytical expressions for the solar cell current-voltage characteristics are derived showing clearly the dominating first-order effects on solar cell performance. The derived closed form solutions indicate that in the useful forward voltage range the largest dark current component of this cell is the interface recombination current and that the main contribution to the photocurrent comes from the light generated holes in the c-Si substrate layer. The transfer of holes across the intrinsic layer and over the ΔEv barrier is strongly suppressed resulting in an attenuation of solar cell dark and photocurrent.

CURRENT–VOLTAGE CHARACTERISTICS OF BARIUM POLYMETHACRYLATE

1992 ◽  
Vol 06 (15) ◽  
pp. 955-958 ◽  
Author(s):  
M. H. CHOHAN ◽  
M. ZULFIQAR ◽  
Z. H. SAPRA ◽  
RIZWAN HUSSAIN ◽  
S. ZULFIQAR
Keyword(s):  
Activation Energy ◽  
Voltage Range ◽  
Arrhenius Relation ◽  
Current Voltage ◽  
Current Voltage Characteristics

Current–voltage characteristics of Barium Polymethacrylate (BaPMA) in the form of Al-BaPMA-Al structures have been studied. The currents are measured in the voltage range 10 V–1 kV. At low voltages an ohmic relation is observed and at higher voltages the Poole-Frenkel mechanism is proposed. The mechanism of conduction has been explained on the basis of different current-voltage and current-temperature curves. The activation energy values calculated using Arrhenius relation fall in the range 0.25–2 eV, suggesting a sequence of trapping levels.

scholarly journals Mathematical modeling of electrical parameters of AC–EAF

2019 ◽  
Vol 62 (7) ◽  
pp. 571-577
Author(s):  
B. S. Dmitrievskii ◽  
A. V. Bashkatova
Keyword(s):  
Differential Equation ◽  
Control Systems ◽  
Low Voltage ◽  
Control Object ◽  
Electric Arc ◽  
Arc Length ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Secondary Side ◽  
Object Behavior

The article presents one of the possible options of mathematical model formation of an electric arc steel-making furnace (EAF). A lot of reports on this subject were studied in order to make a model that most accurately reflects the control object behavior (for EAF). The basic building principles demonstrate the fact that the primary element is substitution pattern of electric circuit of the installation. Cassie nonlinear differential equation was used to get a mathematical model of an electric arc. This nonlinear differential equation is very popular among the researchers. Model update is provided by calculating the electrical circuit parameters on the secondary side of transformer low voltage and by studying statistics from home and foreign scientists’ contributions. Different values of the “time-constant” of arc conductivity were used to analyze the control object behavior at different instants of time. It made it possible to take into account the nonstationarity of the state of electrode sheaths that were influenced by external disturbances, temperature variations, pressure and gas composition in the course of production processes. Such an approach made possible to form an aggregate picture of the control object behavior under the conditions of a nonstationary state of the arc combustion area at different stages of melting; to evaluate possible regulation characteristics and to determine control system requirements. The structural scheme of the model of a three-phase AC–EAF was formed. All necessary calculations of circuit elements and modeling were performed using the MATLAB Simulink package. The block diagram includes AC voltage source, direct-current resistance, and inductance of the transformer on secondary side and a low-voltage circuit, a model of an AC electric arc. The model was used to analyze the dynamic characteristics of electric arc as being an electrical object to show the voltage–dependence of current – current-voltage characteristics. The configuration of current-voltage characteristics determines burning behavior of the arc, existence domain, stability and control quality. Current-voltage characteristics were studied under the conditions of different values of the voltage on the secondary side of transformer and arc length and for different values of the “time-constant arc conductivity”. The model was also used to analyze the static characteristics. The dependence of the arc length on the current for different voltage of the transformer steps is nonlinear. Recommendations on the choice of control actions and the construction of control systems for different stages of melting are given. For example at the initial stage of melting, the control system should perform minimization problems of number of breaks under the condition of an insignificant domain of the arc existence and limit the value of lead-in power. The simulation results show that the nonstationarity of the process leads to the need to use self-organizing control systems capable of adjusting to the continually varying state of the object.

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