Influence of the Magnetic Field and Optimum Base Thickness of a Series Vertical-Junction Silicon Solar Cell under Polychromatic Illumination and Magnetic Field on Capacitance: Determination of Transition and Dark Capacitances

In this paper, we have studied the influence of the optimum thickness of the base of a series vertical-junction solar cell, under polychromatic illumination and magnetic field, on transition and dark capacitances. The expressions for minority carrier density, photovoltage, and capacitance are derived by solving the diffusion equation for minority carriers, based on boundary conditions involving recombination velocities at the junction (Sf) and in the back zone (Sb). The profile of capacitance versus photovoltage for each value of optimum thickness obtained from the magnetic field is then presented, in order to determine the value of transition and dark capacitances for each value of optimum thickness. The evolution of open-circuit photovoltage (Vco) as a function of magnetic field and optimum base thickness is described at the end.