Grégoire Sissoko

Three-dimensional study of a polycrystalline silicon solar cell: the influence of the applied magnetic field on the electrical parameters

In this paper, we present a theoretical 3D study of a polycrystalline silicon solar cell in frequency modulation under polychromatic illumination and applied magnetic field. The influence of the applied magnetic field on the diode current density, Jd, and both electric power–photovoltage and photocurrent–photovoltage characteristics are discussed. The Nyquist diagram permitted us to determine the electrical parameters such as the series resistance Rs and parallel equivalent resistance Rp of a polycrystalline silicon solar cell. The Bode diagram is then used to calculate the cut-off frequency, capacitance C and inductance L. It has been shown that, under a magnetic field, the solar cell behavior is like that of a low-pass filter.

Diffusion Coefficient Modeling of a Silicon Solar Cell under Irradiation Effect in Frequency: Electric Equivalent Circuit

In this paper, a theory on the determination of the diffusion coefficient of the excess minority carriers of a silicon solar cell is presented. The expression of the diffusion coefficient, related to the modulation frequency, the irradiation energy and the damage coefficient is studied and then performed by using the impedance spectroscopy method and Bode and Nyquist diagrams. Based on the diffusion coefficient, we deduce the diffusion length, the cutoff frequency and some electrical parameters obtained from the equivalent circuits of the diffusion coefficient.

Study of base doping rate effect on parallel vertical junction silicon solar cell under magnetic field

In this work we suggest looking for influences of a constant magnetic field and the base doping rate on a parallel vertical junction silicon solar cell under multispectral illumination in static regime. A study on the coefficient and the length diffusion according to the magnetic field B and the doping rate Nb is made. The minority carriers density in the base was studied according to the depth of the base for various values of the base doping rate and the magnetic field. This study allows us to determine the influences of the doping rate and the magnetic field on the photocurrent density, the photovoltage, the space charge region capacitance.The study of these electrical parameters is done according to the concept of the junction surface recombination velocity of excess minority carriers. The logarithm of the capacitance versus photovoltage leads to transitional capacitance.

Analysis of T-Coefficients Using the Columnar Cylindrical Orientation of Solar Cell Grain

We report the study of the temperature dependance of the performance electronic parameters of an N-P solar cell by considering as model, the columnar cylindrical orientation associated to the dynamic junction velocity (SF) concept. We presented the photocurrent-photovoltage (I-V) and Power-photovoltage (P-V) characteristic curves. The short-circuit photocurrent (Isc), the open circuit photovoltage (Uoc), the fill factor (FF) and the efficiency (η) are linearly dependent on the temperature. The temperature coefficients (T-coefficient) relative to the short-circuit, open-circuit photovoltage and efficiency are calculated and the comparison with data from the literature showed the accuracy of the considered model.

Irradiation Energy Effect on a Silicon Solar Cell: Maximum Power Point Determination

The aim of this study is to determinate the electrical parameters of a white biased silicon solar cell submitted to an irradiation energy of particles (protons, helium, electrons and heavy ions). A theoretical study of the influence of irradiation energy on the photocurrent density, the photovoltage, the maximum power, as well as the maximum efficiency of the solar cell is presented through a resolution of the continuity equation relative to excess minority carrier. Then the expressions of the photocurrent density Jph, the photovoltage Vph, and the excess minority carrier recombination velocity at the back side Sb are established dependent of irradiation parameters ∅p, Kl respectively irradiation flux and intensity. In this work, we propose a method for determining the recombination velocity of the excess minority carrier at the junction Sfmax corresponding to the maximum power point delivered by the photovoltaic generator under the influence of the irradiation. It is then obtained by calculating the derivative of the power with respect to the excess minority carrier recombination velocity Sf at the junction emitter-base. A transcendental equation solution is deduced as eigenvalue, leading to the junction recombination velocity of excess minority carrier and also yields the solar cell maximum conversion efficiency.

Junction Surface Recombination Concept as Applied to Silicon Solar Cell Maximum Power Point Determination Using Matlab/Simulink: Effect of Temperature

In this work, we study the method for determining the maximum of the minority carrier recombination velocity at the junction Sfmax, corresponding to the maximum power delivered by the photovoltaic generator. For this, we study the temperature influence on the behavior of the front white biased solar cell in steady state. By solving the continuity equation of excess minority carrier in the base, we have established the expressions of the photocurrent density, the recombination velocity on the back side of the base Sb, and the photovoltage. The photocurrent density and the photovoltage are plotted as a function of Sf, called, minority carrier recombination velocity at the junction surface, for different temperature values. The illuminated I-V characteristic curves of the solar cell are then derived. To better characterize the solar cell, we study the electrical power delivered by the base of the solar cell to the external charge circuit as either junction surface recombination velocity or photovoltage dependent. From the output power versus junction surface recombination velocity Sf, we have deduced an eigenvalue equation depending on junction recombination velocity. This equation allows to obtain the maximum junction recombination velocity Sfmax corresponding to the maximum power delivered by the photovoltaic generator, throughout simulink model. Finally, we deduce the conversion efficiency of the solar cell.

Theoretical study of the thermal behavior of a supple road structure in frequency dynamic modulation under illumination and shade: determination of the temperatures and the flow densities in the interfaces

The determination of the mechanical parameters for the sizing of a road allows, according to the traffic to choose the minimal thickness for various layers. These parameters vary according to the climatic measurement in strong thermal stress zone (illumination) or in of low thermal stress zone (shade) In this work, a theatrical study on the temperature variation and the flow density determination method for every interface of the road structure is proposed in frequency dynamic modulation. This method highlights the influence of the climatic parameters such as the thermal exchange coefficient by radiation and the thermal exchange coefficient by convection.

Thermal impedance spectroscopy method as applied for road bearing layer structure thermoelectric parameters determination

In this article, we propose to determine by thermal electricanalogy of the thermoelectric parameters of a road bearing layer structure from the thermal impedance spectroscopy method. When the road surface is submitted to thermal constraints, a heat exchange phenomenon appears to be characterized by the radiation thermal exchange coefficient and the convection thermal exchange coefficient. The influenceof one of these coefficients compared with the other one on the road depends on its environment (shade or illumination). The determination of the thermal electric parameters allow the valid bearing layer thermal stability. The method used is the thermal impedance spectroscopy method.