Photovoltaic cell

1. A photo-voltaic cell comprising:

a semi-conductor body having first and second surfaces opposite to each other;

first and second two-dimensional arrays of contact points on the first surface, each two-dimensional array of contact points coupled to a respective one of base and emitter areas in or on the semi-conductor body;

electrically separate first and second conductor structures, both on the first surface of the semi-conductor body, on respective ones of the base and emitter areas and coupled to contact points of the first and second two-dimensional arrays, respectively;

the first and second conductor structures forming a two-dimensionally periodic pattern of contiguous, equally shaped, rectangular or hexagonal unit cells on the first surface of the semi-conductor body, wherein

the first conductor structure in each respective one of the unit cells comprises first conductor line branches radiating from the respective one of the contact points of the first two-dimensional array within each respective one of the unit cells in at least three successive different directions at less than a hundred and eighty degrees to each other, and

the second conductor structure comprises conductor lines along borders of the respective one of the unit cells, surrounding the first conductor structure in the respective one of the unit cells, as well as second conductor line branches extending from the borders into the respective one of the unit cells, wherein the second conductor line branches of the second conductor structure extend in at least three different directions in areas between adjacent first conductor line branches in the respective one of the unit cells and wherein at least some of the second conductor line branches of the second conductor structure extend to areas between first conductor line branches of the first conductor structure in each respective one of the unit cells that are adjacent to the second conductor line branches of the second conductor structure, and

wherein the contact points of the second two-dimensional array are located on the borders of the respective one of the unit cells and are in electrical contact with the conductor lines of the second conductor structure.

2. A photo-voltaic cell according to claim 1 , wherein the second conductor line branches of the second conductor structure in the respective one of the unit cells branch into a tree structure with increasing numbers of second conductor line branches with decreasing distance to the respective one of the contact points of the first two-dimensional array in the respective one of the unit cells.

3. A photo-voltaic cell according to claim 2 , wherein at least some of the second conductor line branches in the tree structure of the second conductor structure are bent, at least some of the second conductor line branches have a tip, and the tips of the second conductor line branches are directed at a branch point where a first conductor line branch branches into multiple first conductor line branches.

4. A photo-voltaic cell according to claim 1 , wherein the unit cells are rectangular.

5. A photo-voltaic cell according to claim 1 , wherein the unit cells are hexagonal.

6. A photo-voltaic cell according to claim 1 , wherein at least some of the second conductor line branches of the second conductor structure extend to areas lying between non-parallel adjacent ones of the first conductor line branches of the first conductor structure in the unit cells.

7. A photo-voltaic cell according to claim 1 , wherein the first conductor line branches branch into a tree structure with increasing numbers of first conductor line branches with decreasing distance from the respective one of the contact points of the first two-dimensional array.

8. A photo-voltaic cell according to claim 7 , wherein the tree structure comprises pairs of adjacent first conductor line branches, and wherein the second conductor line branches extend to areas between each pair of adjacent branches in the tree structure.

9. A photo-voltaic cell according to claim 6 , wherein the second conductor line branches in the areas between respective adjacent non-parallel ones of the first conductor line branches extend at least partly along a virtual line that bisects an angle between the adjacent non-parallel ones of the first conductor line branches.

10. A photo-voltaic cell according to claim 1 , wherein the first conductor line branches have mutually equal width.

11. A photo-voltaic cell comprising:

a semi-conductor body having first and second surfaces opposite to each other;

first and second two-dimensional arrays of contact points on the first surface, each two-dimensional array of contact points coupled to a respective one of base and emitter areas in or on the semi-conductor body;

a conductive foil on the first surface, coupled to the contact points of the first two-dimensional array of contact points,

electrically separate first and second conductor structures, both on the first surface of the semi-conductor body, on respective ones of the base and emitter areas and coupled to contact points of the first and second two-dimensional arrays, respectively;

the first and second conductor structures forming a periodic pattern of contiguous rectangular or hexagonal unit cells, wherein

the first conductor structure in each respective one of the unit cells comprises first conductor line branches radiating from the respective one of the contact points of the first two-dimensional array within each respective one of the unit cells in at least three successive different directions at less than a hundred and eighty degrees to each other, and

the second conductor structure comprises conductor lines along borders of the respective one of the unit cells, surrounding the first conductor structure in the respective one of the unit cells, as well as second conductor line branches extending from the borders into the respective one of the unit cells, wherein the second conductor line branches of the second conductor structure extend in at least three different directions in areas between adjacent first conductor line branches in the respective one of the unit cells and wherein at least some of the second conductor line branches of the second conductor structure extend to areas between first conductor line branches of the first conductor structure in each respective one of the unit cells that are adjacent to the second conductor line branches of the second conductor structure, and

wherein the contact points of the second two-dimensional array are located on the borders of the respective one of the unit cells and are in electrical contact with the conductor lines of the second conductor structure.