Electrically independent subcircuits for a seven-junction spectrum splitting photovoltaic module

An electrical system that facilitates independent electrical connection of subcells with different bandgaps is required in order to optimally extract two-terminal power generated by spectrum-splitting photovoltaics. We have designed such a system for a seven subcell spectrum-splitting module using commercially available electrical components. Modified detailed balance modeling of the subcells coupled with HSPICE circuit simulation results in 87.5% power-weighted average subcell-to-grid electrical efficiency. Additional analysis indicates electrical efficiencies in excess of 95% are possible with custom power conditioning components and appropriately designed contacts.