Minimization of the effect of the collecting grid in a solar cell based silicon

Abstract The solar cells collecting grids present a serious problem and more particularly under solar concentration. Our contribution in this article is to seek the best compromise between shadow effect and series resistance effect. The cell considered here is of Si (silicon) type, n + p with circular geometry (radius a = 4.9 cm ), a silver metallization ( ρ M = 1.6 × 1 0 - 6 Ω cm ), and a contact resistivity of ρ C = 1 0 - 5 Ω cm . Our calculations are made under the condition of AM1.5 with 1 sun concentration. The various power losses caused by this grid are: • losses due to the grid shadow, • losses in grain boundaries due to the metal/semiconductor contact, • power dissipated in the resistance of layer between bars, and • losses in the grid metallization. We summarize the results of our model by: • For a sheet resistance ρ S =10 Ω/□: τ oop (%) (optimum shadow fraction)= τ cop (%) (optimum conduction fraction)=5.086% leading to θ optimum =0.0652 rad. • For a sheet resistance ρ S =20 Ω/□: τ oop (%)= τ cop (%)=5.338% leading to θ optimum =0.05883 rad. • For a sheet resistance ρ S =50 Ω/□: τ oop (%)= τ cop (%)=5.949%, θ optimum =0.0500 rad.