NOVELTY - The photovoltaic cell has a first conductor structure with sets of line branches, each branching out from a respective one of a first two-dimensional array of contact points in at least three successive different directions at less than 180 degrees to each other. A second conductor structure comprises line branches in at least three different locations in areas between respective pairs of adjacent first conductor line branches. The first conductor line branches include pairs that each second conductor line branch coupled at least to a respective contact point of a second two-dimensional array.    USE - Photovoltaic cell.    ADVANTAGE - Enables provision of a photovoltaic cell in which currents of both polarities can be collected from the back surface with less loss. Negates need for a broad bus bar since the first conductor line branches branch out from the contact point in multiple directions, of which the first conductor line branches may have equal width and may be provided, for example, in directions radiating from the contact point. Ensures that the base area is kept as small as possible to prevent electrical shading, e.g. enhanced recombination in the base or at the surface. The first conductor line branches branch into a tree structure with increasing numbers of branch conductor lines with distance from the respective one of the contact points, thus realizing a first conductor structure with substantially uniform density, so that the maximum distance from surface points on the first surface to the first conductor structure does not need to become large for surface points further away from the contact point. The second conductor line branches extend to areas between each pair of adjacent branches in the tree structure, thus, the maximum distance from surface points on the first surface to the second conductor structure does not need to become large for surface points closer to the contact point. The first conductor line branches the second conductor line branches in the areas between the respective pairs of adjacent non-parallel ones of the first conductor line branches extend at least partly along a virtual line that bisects an angle between the first conductor line branches in the pair, thus, the maximum distances between the conductor line branches may be kept small with minimal conductor area.    DESCRIPTION OF DRAWING(S) - The drawing shows the plan view of the back surface of a photovoltaic cell with an array structure.    Back surface of photovoltaic cell (10)    First contacts (12)    Second contacts (14)