Method for manufacturing a metallization pattern on a photovoltaic cell

Method for applying a metallization in accordance with a pattern of a system of mutually connected electrical conductors for transporting electrical charge carriers on at least one of the outer surfaces of a photovoltaic element, wherein the conductors display a series resistance and cover a part of the at least one outer surface in accordance with a degree of covering and cause shadow and resistance losses, which method comprises the steps of:

• (i) providing said photovoltaic element, at least one of the outer surfaces of which is a front surface of the photovoltaic element adapted to receive incident light, the front surface being adapted for applying of a metallization thereto, and
• (ii) applying a metallization in accordance with a pattern on the front surface, characterized in that
• the metallization is applied in the second step (ii) in accordance with an optimized pattern which is obtained by determining the thickness d(x,y) as a function of the location (x,y) on said front surface of a light-transmitting metallization layer which completely covers said front surface and allows through a fraction of a quantity of incident light corresponding with said degree of covering, in a manner such that the sum (Pm+Ps) is minimal, in which Pm represents the resistance losses P m = ∫ S ⁢ 1 ρ sm ⁡ ( x , y ) ⁢ ( ∇ → ⁢ V ⁡ ( x , y ) ) 2 ⁢ ⅆ x ⁢ ⅆ y
• and Ps represents either shadow losses
• Ps=∫sPs(x, y)JmpVmpdxdy
• or an efficiency loss
• ∫sPs(x,y) JmpVmpFcdxdy
• for the quantity of material for the metallization, which would occur in the photovoltaic element in operative state, and by deriving from the thickness d(x,y) as a function of the location (x,y) the geometry of a pattern of a system of mutually connected electrical conductors, in which equations S is the surface of the photovoltaic element, Ps(x,y) represents a shadow fraction, Jmp and Vmp respectively represent the local current density and the voltage at the maximum power generated by the element, ρsm(x,y) represents the surface resistance, V(x,y) represents a voltage distribution and Fc is a dimensionless parameter which relates the quantity of material for the metallization to an efficiency loss.