Mamadou Wade

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.

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.