Biohybrid, Photoelectrochemical Energy Conversion Device Based on Photosystem I Deposited Silicon Electrodes


A research team at Vanderbilt University have developed a biohybrid, photoelectrochemical energy conversion device with multilayer films of Photosystem I (PSI) deposited on silicon electrodes, which yielded an average photocurrent density of 875 µA/cm2; one of the highest reported photocurrent densities for a film of PSI deposited onto an electrode of any material.


  • PSI (a membrane protein found in photosynthetic organisms) holds promise as an energy conversion material in a variety of optoelectronics applications due to high quantum efficiency (near 100%)
  • Immobilization of PSI onto an electrode increases the surface concentration of the protein and bring the photoactive material in close contact with the electrode
  • Although a variety of methods have been developed for immobilizing PSI on metal substrates, immobilizing PSI onto semiconducting electrodes have not been very successful with very low efficiencies and short lifetimes

Technology Description

Inventors tested a wide variety of electrodes, both metal and semiconductor, for immobilizing PSI by vacuum assisted dropcast method. Silicon was identified to be a potential candidate due to ability to alter its electronic properties via doping. Inventors have identified the doping type and doping densities in silicon for optimization of photocurrent from the device.The system was further improved by determining the optimal thickness of the protein film and the concentration of the redox mediator (Methyl viologen) to achieve a photo current density of 875 µA/cm2.

Unique Properties and Applications

  • Ability to use multiple layers as opposed to typical dye-sensitized solar cells which are limited to using a monolayer film. PSI acts as an independent photodiode that can separate charge and perform electron transfer reactions without rapid recombination within the protein complex

Both PSI and silicon are widely abundant and when used in conjunction, it provides a promising avenue toward inexpensive solar conversion devices
  • Potential applications for this system include photovoltaic and photodetection devices such as spatial imaging devices, solar batteries, optical computing and logic gates, optoelectronic switches, photonic A/D converters, and thin film flexible photovoltaic structures

  • Intellectual Property Status

    • U

    S provisional application has been filed in 2012
  • Link to publication in Advanced Materials 

  • Link to inventor bios & list of publications

  • Inventors: 
    David CliffelGabriel LeBlancGannon Kane JenningsGongping Chen
    Licensing manager: 
    Chris Harris

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