Panagiota Papadopoulou | Technological Educational Institute of Kavala (original) (raw)
Papers by Panagiota Papadopoulou
Journal of Engineering Science and Technology Review, 2009
European Journal of Scientific Research, 2009
ABSTRACT Some special characteristics of electromagnetic response of stratified dielectric struct... more ABSTRACT Some special characteristics of electromagnetic response of stratified dielectric structures in the frequency domain are studied. We consider Transverse Electric type plane waves incident obliquely on dielectric slabs or more complicated half spaces. The study of zeros and periodicities in these configurations can show the similarities as well as the differences from the Transverse Magnetic type plane waves. The role of non – ideal dielectrics is catalytic, because it causes the degeneration of both the zeros and the periodicities of the reflection coefficient.
Acta Physica Polonica Series a
In this report, a study of the electrical behavior for the Metal/a-SiC/poly-Si(n) structure, appe... more In this report, a study of the electrical behavior for the Metal/a-SiC/poly-Si(n) structure, appears. Di�erent thicknesses of a-SiC:H thin lms are considered; in speci c the a-SiC:H layer thickness is varied between 100 Å up to 800 Å. The 2-D ATLAS advanced numerical simulator has been utilized in order to simulate the material's electrical behavior and produce the reported hereby results. The study of the I-V (current-voltage) characteristics of these Metal/a�-SiC:H/poly-Si(N) structures, reveals a very interesting hysteretic behavior that is a function of the a-SiC:H thin- lm thickness. Such materials have lately raised the engineering community's interest because of their possible utilization as memristive elements.
European Journal of Scientific Research
Some special characteristics of electromagnetic response of stratified dielectric structures in t... more Some special characteristics of electromagnetic response of stratified dielectric structures in the frequency domain are studied. We consider Transverse Electric type plane waves incident obliquely on dielectric slabs or more complicated half spaces. The study of zeros and periodicities in these configurations can show the similarities as well as the differences from the Transverse Magnetic type plane waves. The role of non – ideal dielectrics is catalytic, because it causes the degeneration of both the zeros and the periodicities of the reflection coefficient.
In this paper, an extensive study of the transient optical response speed of silicon Bulk–Barrier... more In this paper, an extensive study of the transient optical response speed of silicon Bulk–Barrier Diodes (BBDs) is presented. This study is based on the simulation results obtained with a 2-D device simulator (S-PISCES and LUMINOUS). The influence of significant quantities, as the applied voltage, the incident light power and the light wavelength, on the optical response speed of silicon Bulk–Barrier Diodes was investigated. As a result of this study we propose a model that calculates the cut–off frequency (optical response speed) of silicon BBDs when a modulated light is applied. Simulation results verify the validity of the proposed model and show that it is possible to achieve high speed optical response by choosing appropriate operational parameters.
Chaos and Complex Systems, 2012
ABSTRACT In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for diffe... more ABSTRACT In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for different values of density of gap states (N) in a-SiC:H, is simulated and studied. It is observed that as the density of gap states in a-SiC:H increases from 10�15 cm�3 to 10�18 cm�3 the I-V characteristics, in the forward bias, present a deviation from the typical I-V of a diode, which is enhanced with the increase of N. For N D 10�18 cm�3 the forward I-V characteristic shows strong chaotic vibration that is attributed to the tunneling effect taking place in the junction a-SiC:H/c-Si(n) in the forward bias.With the method of delays correlation and minimum embedding dimension are calculated, while the influence of gap states in strengthening chaos is studied.
Microelectronics Journal, 2002
ABSTRACT Some articles of this volume will be reviewed individually. For the preceding conference... more ABSTRACT Some articles of this volume will be reviewed individually. For the preceding conference see [Zbl 1244.37003].
Journal of Engineering Science and Technology Review, 2016
In the present work the development of a new, very low cost, simple to manufacture and use, optic... more In the present work the development of a new, very low cost, simple to manufacture and use, optical sensing device for remote, on line detection of the type of fuels used in ships, is presented. The main goal of this optical sensing device is the on line detection of the fuel optical absorption that is used by the ship. The basic operating principle of the proposed sensor is based on different absorption in the range of visible spectrum between bunker diesel and fuel oil. Experimental measurements, using monochromatic laser light or white led light, have shown that the proposed sensor can distinguish very accurately the difference between the two types of oil, giving the advantage to detect the type of fuel.
In the present work the development of a new, very low cost, simple to manufacture and use, optic... more In the present work the development of a new, very low cost, simple to manufacture and use, optical sensing device for remote, on line detection of the type of fuels used in ships, is presented. The main goal of this optical sensing device is the on line detection of the fuel optical absorption that is used by the ship. The basic operating principle of the proposed sensor is based on different absorption in the range of visible spectrum between bunker diesel and fuel oil. Experimental measurements, using monochromatic laser light or white led light, have shown that the proposed sensor can distinguish very accurately the difference between the two types of oil, giving the advantage to detect the type of fuel.
Chaos and Complex Systems, 2012
In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for different valu... more In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for different values of density of gap states (N) in a-SiC:H, is simulated and studied. It is observed that as the density of gap states in a-SiC:H increases from 10 15 cm 3 to 10 18 cm 3 the I-V characteristics, in the forward bias, present a deviation from the typical I-V of a diode, which is enhanced with the increase of N. For N D 10 18 cm 3 the forward I-V characteristic shows strong chaotic vibration that is attributed to the tunneling effect taking place in the junction a-SiC:H/c-Si(n) in the forward bias. With the method of delays correlation and minimum embedding dimension are calculated, while the influence of gap states in strengthening chaos is studied.
The paper presents the details of trend trading algorithm in futures market. A contribution of th... more The paper presents the details of trend trading algorithm in futures market. A contribution of this paper lies in a modified chart pattern related to a fractal formation, nonlinearity and chaos theory, broadly discussed by Benoit B.Mandelbrot and Bill M. Williams. As typical fractal pattern often is being applied in conjunction with other forms of technical analysis, like moving averages, Elliott Waves analysis or MACD indicators the proposed pattern is presented as a basic indicator itself. The strategy can be applied as up-trend market forecasting tool. The efficiency of the proposed strategy was tested with the most active North American futures contracts using 10 years historical daily data. Experimental results showed better returns if compared to overall market average-CRB index.
In this report, a study of the electrical behavior for the Metal/a-SiC/poly-Si(n) structure, appe... more In this report, a study of the electrical behavior for the Metal/a-SiC/poly-Si(n) structure, appears. Dierent
thicknesses of a-SiC:H thin lms are considered; in speci c the a-SiC:H layer thickness is varied between 100 Å
up to 800 Å. The 2-D ATLAS advanced numerical simulator has been utilized in order to simulate the material's
electrical behavior and produce the reported hereby results. The study of the IV (current-voltage) characteristics
of these Metal/a -SiC:H/poly-Si(N) structures, reveals a very interesting hysteretic behavior that is a function of
the a-SiC:H thin- lm thickness. Such materials have lately raised the engineering community's interest because of
their possible utilization as memristive elements.
In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for different valu... more In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for different values of density of gap states (N) in a-SiC:H, is simulated and studied. It is observed that as the density of gap states in a-SiC:H increases from 10 15 cm 3 to 10 18 cm 3 the I-V characteristics, in the forward bias, present a deviation from the typical I-V of a diode, which is enhanced with the increase of N. For N D 10 18 cm 3 the forward I-V characteristic shows strong chaotic vibration that is attributed to the tunneling effect taking place in the junction a-SiC:H/c-Si(n) in the forward bias. With the method of delays correlation and minimum embedding dimension are calculated, while the influence of gap states in strengthening chaos is studied.
Journal of Engineering Science and Technology Review, Vol. 2, pp. 157-164, (2009).
In this paper, it is studied for the first time, the possibility of manufacturing a Bulk Barrier ... more In this paper, it is studied for the first time, the possibility of manufacturing a Bulk Barrier diode in planar technology using simulation. This study is based on simulation results obtained with a 2-D device simulator (S-PISCES). More precisely, the electrical and switching behavior of the proposed devices in planar technology were investigated. The results of this study show that the technological parameters (doping concentrations), as well as the geometrical sizes (middle region width) and the bias conditions (applied voltage), have significant effects on the electrical and switching behavior of the proposed devices. The appropriate choice of these parameters can reduce the switching time in the range of few picoseconds and also dramatically modify the current through the device. The simulation results of devices in planar technology have been compared with those designed in non planar technology. Finally, good agreement among theory and simulations results of the proposed devices observed.
OPTOELECTRONICS AND ADVANCED MATERIALS - RAPID COMMUNICATIONS Vol. 1, No. 8, p. 379 -384 (2007).
In this paper, an extensive study of the transient optical response speed of silicon Bulk-Barrier... more In this paper, an extensive study of the transient optical response speed of silicon Bulk-Barrier Diodes (BBDs) is presented. This study is based on the simulation results obtained with a 2-D device simulator (S-PISCES and LUMINOUS). The influence of significant quantities, as the applied voltage, the incident light power and the light wavelength, on the optical response speed of silicon Bulk-Barrier Diodes was investigated. As a result of this study we propose a model that calculates the cut-off frequency (optical response speed) of silicon BBDs when a modulated light is applied. Simulation results verify the validity of the proposed model and show that it is possible to achieve high speed optical response by choosing appropriate operational parameters.
European Journal of Scientific Research, Vol. 34, No.4, pp. 463-473 (2009)
Some special characteristics of electromagnetic response of stratified dielectric structures in t... more Some special characteristics of electromagnetic response of stratified dielectric structures in the frequency domain are studied. We consider Transverse Electric type plane waves incident obliquely on dielectric slabs or more complicated half spaces. The study of zeros and periodicities in these configurations can show the similarities as well as the differences from the Transverse Magnetic type plane waves. The role of non -ideal dielectrics is catalytic, because it causes the degeneration of both the zeros and the periodicities of the reflection coefficient.
Thin Solid Film, Vol. 415, pp. 276-284 (2002)
In this paper, an extensive study of the photocurrent amplification mechanism of silicon bulk-bar... more In this paper, an extensive study of the photocurrent amplification mechanism of silicon bulk-barrier diodes (BBDs) is presented, based on simulation and experimental results. As a result of this study an analytical model is proposed. The proposed model extends previously published models and includes analytical expressions for all significant quantities of the device optoelectronic behaviour. Such quantities are barrier lowering, photocurrent, quantum efficiency and response speed as functions of the applied voltage, incident light power, light wavelength and modulation frequency, as well as a function of technological parameters. Simulation and experimental results verify the validity of the proposed analytical model, and they show that BBDs are majority carrier photodetectors with high internal photocurrent gain. Compared with common photodetectors, BBDs exhibit a very high sensitivity in the blue region of the visible spectrum. ᮊ
Journal of Engineering Science and Technology Review, 2009
European Journal of Scientific Research, 2009
ABSTRACT Some special characteristics of electromagnetic response of stratified dielectric struct... more ABSTRACT Some special characteristics of electromagnetic response of stratified dielectric structures in the frequency domain are studied. We consider Transverse Electric type plane waves incident obliquely on dielectric slabs or more complicated half spaces. The study of zeros and periodicities in these configurations can show the similarities as well as the differences from the Transverse Magnetic type plane waves. The role of non – ideal dielectrics is catalytic, because it causes the degeneration of both the zeros and the periodicities of the reflection coefficient.
Acta Physica Polonica Series a
In this report, a study of the electrical behavior for the Metal/a-SiC/poly-Si(n) structure, appe... more In this report, a study of the electrical behavior for the Metal/a-SiC/poly-Si(n) structure, appears. Di�erent thicknesses of a-SiC:H thin lms are considered; in speci c the a-SiC:H layer thickness is varied between 100 Å up to 800 Å. The 2-D ATLAS advanced numerical simulator has been utilized in order to simulate the material's electrical behavior and produce the reported hereby results. The study of the I-V (current-voltage) characteristics of these Metal/a�-SiC:H/poly-Si(N) structures, reveals a very interesting hysteretic behavior that is a function of the a-SiC:H thin- lm thickness. Such materials have lately raised the engineering community's interest because of their possible utilization as memristive elements.
European Journal of Scientific Research
Some special characteristics of electromagnetic response of stratified dielectric structures in t... more Some special characteristics of electromagnetic response of stratified dielectric structures in the frequency domain are studied. We consider Transverse Electric type plane waves incident obliquely on dielectric slabs or more complicated half spaces. The study of zeros and periodicities in these configurations can show the similarities as well as the differences from the Transverse Magnetic type plane waves. The role of non – ideal dielectrics is catalytic, because it causes the degeneration of both the zeros and the periodicities of the reflection coefficient.
In this paper, an extensive study of the transient optical response speed of silicon Bulk–Barrier... more In this paper, an extensive study of the transient optical response speed of silicon Bulk–Barrier Diodes (BBDs) is presented. This study is based on the simulation results obtained with a 2-D device simulator (S-PISCES and LUMINOUS). The influence of significant quantities, as the applied voltage, the incident light power and the light wavelength, on the optical response speed of silicon Bulk–Barrier Diodes was investigated. As a result of this study we propose a model that calculates the cut–off frequency (optical response speed) of silicon BBDs when a modulated light is applied. Simulation results verify the validity of the proposed model and show that it is possible to achieve high speed optical response by choosing appropriate operational parameters.
Chaos and Complex Systems, 2012
ABSTRACT In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for diffe... more ABSTRACT In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for different values of density of gap states (N) in a-SiC:H, is simulated and studied. It is observed that as the density of gap states in a-SiC:H increases from 10�15 cm�3 to 10�18 cm�3 the I-V characteristics, in the forward bias, present a deviation from the typical I-V of a diode, which is enhanced with the increase of N. For N D 10�18 cm�3 the forward I-V characteristic shows strong chaotic vibration that is attributed to the tunneling effect taking place in the junction a-SiC:H/c-Si(n) in the forward bias.With the method of delays correlation and minimum embedding dimension are calculated, while the influence of gap states in strengthening chaos is studied.
Microelectronics Journal, 2002
ABSTRACT Some articles of this volume will be reviewed individually. For the preceding conference... more ABSTRACT Some articles of this volume will be reviewed individually. For the preceding conference see [Zbl 1244.37003].
Journal of Engineering Science and Technology Review, 2016
In the present work the development of a new, very low cost, simple to manufacture and use, optic... more In the present work the development of a new, very low cost, simple to manufacture and use, optical sensing device for remote, on line detection of the type of fuels used in ships, is presented. The main goal of this optical sensing device is the on line detection of the fuel optical absorption that is used by the ship. The basic operating principle of the proposed sensor is based on different absorption in the range of visible spectrum between bunker diesel and fuel oil. Experimental measurements, using monochromatic laser light or white led light, have shown that the proposed sensor can distinguish very accurately the difference between the two types of oil, giving the advantage to detect the type of fuel.
In the present work the development of a new, very low cost, simple to manufacture and use, optic... more In the present work the development of a new, very low cost, simple to manufacture and use, optical sensing device for remote, on line detection of the type of fuels used in ships, is presented. The main goal of this optical sensing device is the on line detection of the fuel optical absorption that is used by the ship. The basic operating principle of the proposed sensor is based on different absorption in the range of visible spectrum between bunker diesel and fuel oil. Experimental measurements, using monochromatic laser light or white led light, have shown that the proposed sensor can distinguish very accurately the difference between the two types of oil, giving the advantage to detect the type of fuel.
Chaos and Complex Systems, 2012
In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for different valu... more In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for different values of density of gap states (N) in a-SiC:H, is simulated and studied. It is observed that as the density of gap states in a-SiC:H increases from 10 15 cm 3 to 10 18 cm 3 the I-V characteristics, in the forward bias, present a deviation from the typical I-V of a diode, which is enhanced with the increase of N. For N D 10 18 cm 3 the forward I-V characteristic shows strong chaotic vibration that is attributed to the tunneling effect taking place in the junction a-SiC:H/c-Si(n) in the forward bias. With the method of delays correlation and minimum embedding dimension are calculated, while the influence of gap states in strengthening chaos is studied.
The paper presents the details of trend trading algorithm in futures market. A contribution of th... more The paper presents the details of trend trading algorithm in futures market. A contribution of this paper lies in a modified chart pattern related to a fractal formation, nonlinearity and chaos theory, broadly discussed by Benoit B.Mandelbrot and Bill M. Williams. As typical fractal pattern often is being applied in conjunction with other forms of technical analysis, like moving averages, Elliott Waves analysis or MACD indicators the proposed pattern is presented as a basic indicator itself. The strategy can be applied as up-trend market forecasting tool. The efficiency of the proposed strategy was tested with the most active North American futures contracts using 10 years historical daily data. Experimental results showed better returns if compared to overall market average-CRB index.
In this report, a study of the electrical behavior for the Metal/a-SiC/poly-Si(n) structure, appe... more In this report, a study of the electrical behavior for the Metal/a-SiC/poly-Si(n) structure, appears. Dierent
thicknesses of a-SiC:H thin lms are considered; in speci c the a-SiC:H layer thickness is varied between 100 Å
up to 800 Å. The 2-D ATLAS advanced numerical simulator has been utilized in order to simulate the material's
electrical behavior and produce the reported hereby results. The study of the IV (current-voltage) characteristics
of these Metal/a -SiC:H/poly-Si(N) structures, reveals a very interesting hysteretic behavior that is a function of
the a-SiC:H thin- lm thickness. Such materials have lately raised the engineering community's interest because of
their possible utilization as memristive elements.
In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for different valu... more In this paper the electrical behavior of the Al/a-SiC:H/c-Si(n) heterojunction for different values of density of gap states (N) in a-SiC:H, is simulated and studied. It is observed that as the density of gap states in a-SiC:H increases from 10 15 cm 3 to 10 18 cm 3 the I-V characteristics, in the forward bias, present a deviation from the typical I-V of a diode, which is enhanced with the increase of N. For N D 10 18 cm 3 the forward I-V characteristic shows strong chaotic vibration that is attributed to the tunneling effect taking place in the junction a-SiC:H/c-Si(n) in the forward bias. With the method of delays correlation and minimum embedding dimension are calculated, while the influence of gap states in strengthening chaos is studied.
Journal of Engineering Science and Technology Review, Vol. 2, pp. 157-164, (2009).
In this paper, it is studied for the first time, the possibility of manufacturing a Bulk Barrier ... more In this paper, it is studied for the first time, the possibility of manufacturing a Bulk Barrier diode in planar technology using simulation. This study is based on simulation results obtained with a 2-D device simulator (S-PISCES). More precisely, the electrical and switching behavior of the proposed devices in planar technology were investigated. The results of this study show that the technological parameters (doping concentrations), as well as the geometrical sizes (middle region width) and the bias conditions (applied voltage), have significant effects on the electrical and switching behavior of the proposed devices. The appropriate choice of these parameters can reduce the switching time in the range of few picoseconds and also dramatically modify the current through the device. The simulation results of devices in planar technology have been compared with those designed in non planar technology. Finally, good agreement among theory and simulations results of the proposed devices observed.
OPTOELECTRONICS AND ADVANCED MATERIALS - RAPID COMMUNICATIONS Vol. 1, No. 8, p. 379 -384 (2007).
In this paper, an extensive study of the transient optical response speed of silicon Bulk-Barrier... more In this paper, an extensive study of the transient optical response speed of silicon Bulk-Barrier Diodes (BBDs) is presented. This study is based on the simulation results obtained with a 2-D device simulator (S-PISCES and LUMINOUS). The influence of significant quantities, as the applied voltage, the incident light power and the light wavelength, on the optical response speed of silicon Bulk-Barrier Diodes was investigated. As a result of this study we propose a model that calculates the cut-off frequency (optical response speed) of silicon BBDs when a modulated light is applied. Simulation results verify the validity of the proposed model and show that it is possible to achieve high speed optical response by choosing appropriate operational parameters.
European Journal of Scientific Research, Vol. 34, No.4, pp. 463-473 (2009)
Some special characteristics of electromagnetic response of stratified dielectric structures in t... more Some special characteristics of electromagnetic response of stratified dielectric structures in the frequency domain are studied. We consider Transverse Electric type plane waves incident obliquely on dielectric slabs or more complicated half spaces. The study of zeros and periodicities in these configurations can show the similarities as well as the differences from the Transverse Magnetic type plane waves. The role of non -ideal dielectrics is catalytic, because it causes the degeneration of both the zeros and the periodicities of the reflection coefficient.
Thin Solid Film, Vol. 415, pp. 276-284 (2002)
In this paper, an extensive study of the photocurrent amplification mechanism of silicon bulk-bar... more In this paper, an extensive study of the photocurrent amplification mechanism of silicon bulk-barrier diodes (BBDs) is presented, based on simulation and experimental results. As a result of this study an analytical model is proposed. The proposed model extends previously published models and includes analytical expressions for all significant quantities of the device optoelectronic behaviour. Such quantities are barrier lowering, photocurrent, quantum efficiency and response speed as functions of the applied voltage, incident light power, light wavelength and modulation frequency, as well as a function of technological parameters. Simulation and experimental results verify the validity of the proposed analytical model, and they show that BBDs are majority carrier photodetectors with high internal photocurrent gain. Compared with common photodetectors, BBDs exhibit a very high sensitivity in the blue region of the visible spectrum. ᮊ