Metal Pillar Interconnection Topology for Bonded Two-Terminal Multijunction III–V Solar Cells

Metal-interconnected multijunction solar cells offer one pathway toward efficiencies in excess of 50%. However, if a three- or four-terminal configuration is used, optical losses from the interfacial grid can be considerable. Here, we examine an alternative that provides an optimal interconnection for two-terminal bonded devices. This “pillar-array” topology is optimized by minimizing the sum of all power losses, including shadow losses and numerically computed electrical losses. Numerical modeling is used to illustrate the benefit of a pillar-array interfacial metallization for some two-terminal configurations.