Integration of Photosystem I Proteins within Conductive Polymer Matrices Using Vapor Phase Techniques

Organic Solvent-Free Integration of Photosystem I Proteins within Conductive Polymer Matrices Using Vapor Phase Techniques

Maxwell Robinson, Evan Gizzie, David Cliffel, and G. Kane Jennings

 

            Photosystem I (PSI) is a 500 kDa photocatalytic protein complex residing within chloroplast granum of photosynthetic organisms, converting incident solar radiation to electrons with near-unity internal quantum efficiency. Extracted PSI has been employed successfully as a molecular photosensitizer within a host of low-cost electrochemical and solid-state photovoltaic architectures.    This presentation explores this group’s recent efforts to assimilate PSI within a chemically and energetically tuned conductive polymer matrix. Composite assembly follows a vapor phase Friedel-Crafts grafting procedure, whereby dispersed Fe(III) catalyzes rapid polymer growth from aromatic moieties inherent to PSI.  The technique avoids temperature and solvent exposure requirements standard to bulk heterojunction fabrication in organic photovoltaics and can be employed using a wide library of high vapor pressure conjugated monomers.  Our composite assemblies enhance charge shuttling processes from individual proteins within multilayer assemblies—greatly reducing charge transfer resistances and improving overall efficiency of photocells.