Patent ID: 6573445
Filing Date: 2003-06-03
Classification: H01L,Y02E

Abstract:
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 Pm=&Integral;S&it;1Ï sm&af;(x,y)&it;(&Del;&RightArrow;&it;V&af;(x,y))2&it;&dd;x&it;&dd;yand Ps represents either shadow lossesPs=âˆ«sPs(x, y)JmpVmpdxdy or an efficiency lossâˆ«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, &rgr;sm(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.