A 3D model for thickness and diffusion capacitance of emitter-base junction determination in a bifacial polycrystalline solar cell under real operating condition

This paper aims at presenting the behaviour of the space charge region for an n^+ -p-p^+ bifacial solar cell under monochromatic illumination. It also deals with mathematical relations in the describing and the use of new approach that involves both junction and back surface recombination velocities with a 3D modelling study. Based on the normalized carriers’ density, versus base depth, the space-charge layer thickness (Z0,u) is studied for various parameters such as grain size g , grain boundaries recombination velocity Sgb, wavelength λ and for different operating conditions. Therefore, the relationship between Z0,u and the diffusion capacitance Cu show that junction in the n^+ -p-p^+ solar cell, with columnar grain orientation, is characterized by the plane capacitor properties.