“…However, current designs still function well below the internal quantum efficiency shown for PSI and photosynthetic charge separation in general, 9,14 suggesting room for device improvement. There are many different approaches being studied for the improvement of PSI-based biohybrid devices, including improving the unidirectionality of deposited PSI on electrodes, 15,16 improvement of the optical cross-section of PSI to increase light harvesting capabilities, 17,18 and interest in creation of solid-state devices [19][20][21] A key area of improvement is in PSI reduction rates to help increase dye regeneration rates. Reduction of T. elongatus PSI by its native biological redox mediator, the one-electron shuttle protein cytochrome c 6 , has (1) PSI absorbs a photon, (2) which then promotes the special chlorophyll pair PSI-P700 to an excited state.…”