Effect of Magnetic Field and Temperature on the Excess Minority Carrier Density in the Base of a Radial Junction Solar Cell

This study presents a theoretical analysis of the combined impact of magnetic field and temperature on the charge carrier density in polycrystalline silicon radial‐junction solar cells. Based on a two‐dimensional model in the transient dynamic regime, the continuity equation is solved using the method of separation of variables combined with Bessel functions, taking into account the radial geometry. Unlike planar cells, the radial structure of solar cells allows the decoupling of light absorption from charge collection, thus enabling the use of lower‐purity materials while improving collection efficiency. The results show that the electron density decreases with increasing radial distance. However, it increases with the magnetic field intensity up to a threshold of 2 × 10 −3 T. This effect, more pronounced at larger radii, is explained by the Lorentz force, which confines the electrons. Carrier density also increases with temperature. Nevertheless, within the range from B = 1 × 10 −4 T to approximately B ≈ 5.6 × 10 −4 T, it becomes nearly insensitive to thermal variations. Although purely theoretical and not accounting for certain effects (such as surface recombination), this study provides a relevant analytical framework for optimizing radial solar cells. Experimental validation remains to be considered.