Controlling The Lateral Photoeffect In a-Si:H Heterojunction Structures: The Influence of The Band Offset Analysed Through A Numerical Simulation

2001 ◽  
Vol 664 ◽  
Author(s):  
A. Fantoni ◽  
M. Fernandes ◽  
P. Louro ◽  
R. Schwarz ◽  
M. Vieira
Keyword(s):  
Electric Field ◽  
Incident Light ◽  
Lateral Diffusion ◽  
Field Vector ◽  
Band Offset ◽  
Operation Condition ◽  
Dark Zone ◽  
Incident Light Wavelength ◽  
Local Illumination ◽  
Device Operation

ABSTRACTWhen an a-Si:H p-i-n structure is locally illuminated by a light spot, the non uniformity of light causes the appearance of a gradient in the carrier concentration between the illuminated and the dark zone. Carrier start to flow in agreement with such gradients, and when equilibrium is reached, the lateral diffusion process is counterbalanced by the appearance of a lateral component of the electric field vector in addition to the transverse usual one. The lateral fields act as a gate for the lateral flow of the carriers and small lateral currents appears at the transition region between the illuminated and the dark zone.Such lateral photoeffect depends on the incident light wavelength, light intensity and on the device operation condition (mainly the applied bias). The introduction of carbon in the doped layers modifies the intensity and the extension of these lateral effects through the potential barriers deriving from the band banding at the interfaces.We have used the 2D numerical simulator ASCA to analyze the behavior of an a-Si:H p-i-n structure under local illumination with the goal of observing the appearance of the lateral components of the electric field and current density vectors. Different homo and heterojunctions have been simulated, outlining how the band offset at the interfaces influences the induced lateral photoeffect and aiming to explain how a correct device design and engineering can, depending on the foreseen application, alternatively enhance or reduce the intensity of such lateral effects.

Dependence of the Lateral Photoeffect in a-Si:H P-I-N Structures on the Material Characteristics Studied by Means of a Numerical Simulation

2002 ◽  
Vol 715 ◽  
Author(s):  
A. Fantoni ◽  
M. Fernandes ◽  
M. Vieira
Keyword(s):  
Electric Field ◽  
Incident Light ◽  
Lateral Diffusion ◽  
Field Vector ◽  
Doping Density ◽  
Dark Zone ◽  
Photo Effect ◽  
Incident Light Wavelength ◽  
Local Illumination ◽  
Wavelength Light

AbstractWhen an a-Si:H p-i-n structure is locally illuminated by a light spot, the non uniformity of light causes the appearance of a gradient in the carrier concentration between the illuminated and the dark zone. Carrier start to flow in agreement with such gradients, and when equilibrium is reached, the lateral diffusion process is counterbalanced by the appearance of a lateral component of the electric field vector in addition to the transverse usual one. The lateral fields act as a gate for the lateral flow of the carriers and small lateral currents appears at the transition region between the illuminated and the dark zone. Known as lateral photo-effect, this phenomena depends on the incident light wavelength, light intensity and on the applied bias. Anyway, its intensity can be, depending on the foreseen application, alternatively enhanced or reduced by correct device engineering. We have used the 2D numerical simulator ASCA to analyze the behavior of a-Si:H p-i-n structures under local illumination with the goal of observing the appearance of the lateral components of the electric field and current density vectors. The dependence of the lateral potential redistribution on the doping density, density of defects in the intrinsic layer, and layer thickness have been analyzed. This study aims to show how material properties and device geometry can be combined in order to control the lateral photo-effect.

Light-triggered Silicon-carbon Pi'npin Devices for Optical Communications: Theoretical and Electrical Approaches

2010 ◽  
Vol 1245 ◽  
Author(s):  
Manuela Vieira ◽  
M. A. Vieira ◽  
João Costa ◽  
Paula Louro ◽  
Miguel Fernandes ◽  
...  
Keyword(s):  
Optical Communications ◽  
Incident Light ◽  
Optical Signal ◽  
Nonlinear Dependence ◽  
Light Wavelength ◽  
Electrical Model ◽  
Silicon Carbon ◽  
Light Generation ◽  
Incident Light Wavelength ◽  
Device Operation

AbstractIn this paper a light-activated multiplexer/demultiplexer silicon-carbon device is analysed. An electrical model for the device operation is presented and used to compare output signals with experimental data. An algorithm that takes into accounts the voltage and the optical bias controlled sensitivities is developed. The device is a double pi'n/pin a-SiC:H heterostructure with two optical gate connections for light triggering in different spectral regions. Multiple monochromatic pulsed communication channels were transmitted together, each one with a specific bit sequence. The combined optical signal was analyzed by reading out, under different applied voltages and optical bias, the generated photocurrent across the device. Experimental and simulated results show that the output multiplexed signal has a strong nonlinear dependence on the light absorption profile, i.e. on the incident light wavelength, bit rate and intensity under unbalanced light generation of carriers. By switching between positive and negative voltages the input channels can be recovered or removed from the output signal.

A molecular theory of electromagnetic wave propogation in two-component ansiotropic polymer systems

1962 ◽  
Vol 254 (1044) ◽  
pp. 397-440 ◽  
Keyword(s):  
Electric Field ◽  
Group Structure ◽  
Incident Light ◽  
Pair Correlation ◽  
Internal Field ◽  
Field Vector ◽  
Lattice Points ◽  
Electric Vector ◽  
Internal Electric Field ◽  
Principal Axes

It has been shown by Bragg (1924) that the birefringence of anisotropic crystalline materials can be ascribed in part to the anisotropic dependence of the magnitude of the induced internal electric field on the electric vector of an incident light wave set at differing orientations to the crystalline axes. The internal field depends on positional correlation between pairs of particles, and if this is anisotropic the induced field depends on the relative orientation of the electric vector to the symmetry axes of the pair correlation function. The square, of the refractive index m of the material depends on the ratio of the induced electric field to the applied field, and, when this ratio depends on the orientation of the applied electric field vector, m2 will have tensor-like properties—at least in so far as it will have three (in general) principal axes and values. In condensed phases the spherical symmetry of individual isolated atoms is lost and a second source o f birefringence resides in the ordered orientation o f individually anisotropically polarizable particles. In so far as it is also mathematically convenient, when treating condensed systems, to deal with the polarizability of any group of atoms which retains its group structure over long periods of time as that of a single entity, birefringence must a fortiori be ascribed also to an intrinsic anisotropy of polarizability of individual particles. Nitta (1940) therefore described the observed birefringence in certain tetragonal crystals in terms of an anisotropically polarizable unit corresponding to the content of one unit cell localized on tetragonal lattice points

Instrument for measuring the electric field vector of high-voltage equipment

1983 ◽  
Vol 26 (1) ◽  
pp. 49-50
Author(s):  
I. P. Klimashevskii ◽  
B. L. Kondrat'ev ◽  
V. A. Poletaev ◽  
V. M. Yurkevich
Keyword(s):  
Electric Field ◽  
High Voltage ◽  
Field Vector ◽  
Electric Field Vector

scholarly journals Observation of a comb-shaped filamentary plasma array under subcritical condition in 303-GHz millimetre-wave air discharge

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Masafumi Fukunari ◽  
Shunsuke Tanaka ◽  
Ryuji Shinbayashi ◽  
Yuusuke Yamaguchi ◽  
Yoshinori Tatematsu ◽  
...  
Keyword(s):  
Electric Field ◽  
Focal Point ◽  
Incident Beam ◽  
Wave Structure ◽  
Field Vector ◽  
Interesting Phenomenon ◽  
Millimetre Wave ◽  
Field Plane ◽  
Subcritical Condition ◽  
Air Discharge

AbstractGas breakdown in the millimetre-wave frequency band is an interesting phenomenon in nonlinear dynamics such as self-organized structure formation. We observed the transition between two types of filamentary plasma arrays in air discharge driven by a 303-GHz millimetre wave. Plasma is ignited at a parabolic mirror’s focal point in the overcritical condition. One array parallel to the electric field vector appears with a spacing of λ/4 at the focal point. Filaments then separate into plasma lumps ~10 μs after ignition. At 20 μs, a new comb-shaped array grows in the subcritical condition. Filaments are parallel to the incident beam with spacing of 0.96 λ and elongate towards the incident beam. This comb-shaped array appears only in the electric field plane; bulk plasma with a sharp vertex forms in the magnetic field plane. This array is created by a standing wave structure generated by waves diffracted from the plasma surface. Filamentary plasma array formations can influence the energy absorption by the plasma, which is important for engineering applications such as beamed energy propulsion.

scholarly journals Properties and Analysis of Transparency Conducting AZO Films by Using DC Power and RF Power Simultaneous Magnetron Sputtering

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Neng-Fu Shih ◽  
Jin-Zhou Chen ◽  
Yeu-Long Jiang
Keyword(s):  
Incident Light ◽  
Blue Shift ◽  
Light Wavelength ◽  
Rf Power ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dc Power ◽  
Incident Light Wavelength ◽  
Significant Blue Shift ◽  
Sputtering System

DC power and RF power were introduced into the magnetic controlled sputtering system simultaneously to deposit AZO films in order to get an acceptable deposition rate with high quality transparency conducting thin film. The resistivity decreases with the RF power for the as-deposited samples. The resistivity of 6 × 10−4 Ω-cm and 3.5–4.5 × 10−4 Ω-cm is obtained for the as-deposited sample, and for all annealed samples, respectively. The transmittance of the AZO films with higher substrate temperature is generally above 80% for the incident light wavelength within 400–800 nm. The transmittance of the as-deposited samples reveals a clear blue shift phenomenon. The AZO films present (002) oriented preference as can be seen from the X-ray diffraction curves. All AZO films reveal compressive stress. The annealing process improves the electrical property of AZO films. A significant blue shift phenomenon has been found, which may have a great application for electrode in solar cell.

scholarly journals Numerical simulation of a plasmonic lens for laser light focusing

2021 ◽  
Vol 2103 (1) ◽  
pp. 012174
Author(s):  
E S Kozlova ◽  
V V Kotlyar
Keyword(s):  
Focal Spot ◽  
Laser Light ◽  
Incident Light ◽  
Lens Design ◽  
Light Wavelength ◽  
Optimal Parameters ◽  
Plasmonic Lens ◽  
Radial Polarization ◽  
Incident Light Wavelength ◽  
Difference Time

Abstract In this paper, the design of a plasmonic lens in gold and silver thin films for focusing the light with radial polarization is presented. Using the finite difference time domain method the optimal parameters of the plasmonic lens design are found. It was shown that the silver plasmonic lens produces a tight focal spot with a full width at half maximum of 0.38 of the incident light wavelength.

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