All-perovskite multijunction solar modules that circumvent drawbacks of wide-bandgap top cells

Abstract All-perovskite double- and triple-junction solar modules using monolithically series-interconnected structures provide many advantages including high conversion efficiency, scalability, lightweight, flexibility, etc., However, the wide-bandgap (WBG) top cells currently suffer from insufficiently high efficiency and durability. We proposed module configurations to circumvent these drawbacks of the WBG cells, by introducing an additional design parameter unique to large-sized modules: the subcell-width ratio. The top and bottom modules are designed so that their maximal-power voltages are approximately the same by tuning the subcell widths, and parallel-connected in the voltage-matched (VM) configuration. Another configuration is the series connection of the current-matched (CM) submodules. These configurations yield approximately the same or higher efficiencies as the conventional modules in which all the subcells of the same width are directly series-connected, eliminating the I/Br-phase-segregation problem of the WBG cells. The VM or CM modules are selected depending on the remaining degradation factors of the WBG cells.