Picosecond Electron Transfer from Photosynthetic Reaction Center Protein to GaAs

An extremely fast electron transfer through an electronically coupled junction between covalently bound oriented photosynthetic reaction center protein photosystem I (PS I) and n-GaAs was measured by time-resolved photoluminescence. It was found I hat the n-GaAs band edge luminescence intensity increased by a factor of 2, and the fast exponential decay constant was increased by a factor of 2.6 following the PS I self-assembly. We attribute this to picosecond electron transfer from the PS I to the n-GaAs surface states.