Design guides for artificial photosynthetic devices consisting of voltage-matched perovskite/silicon tandem solar-cell modules and electrochemical-reactor modules

Abstract We clarified the design guides for H2- and CO-producing artificial photosynthetic devices. The combination of a voltage-matched (VM) tandem solar-cell (SC) module and an electrochemical (EC) module was adopted. The parallel-connected top and bottom SC modules, in which multiple organic-inorganic hybrid perovskite (PVK) SCs with a bandgap of 1.7 eV and crystalline-silicon SCs were connected in series, respectively, powered the EC module consisting of series-connected multiple EC reactors. It was found that the design parameters of the series-connection numbers must be optimized under the slightly larger solar intensity and higher temperature than the average values, respectively, for minimizing the mismatch between the device operating voltage and SC maximal-power voltage. This is contrasting to that the annual electricity production of the VM SC module coupled with a power conditioner is not sensitive to the optimization condition. Increases in the bandgaps of the PVK SCs do not affect the annual production significantly.