PEPDIODE · Peptide-based diodes for solar cells

In a solar cell that converts energy as efficient as the natural plant photosystems, electrons should travel over very short distances, through an extremely ordered structure free of traps. Guided by these principles that were worked out at WIS and CUNY, we want to synthesize many different peptides, and consecutively screen variants thereof for a putative diode function. When linked to light-harvesting building blocks, these should yield a novel type of solar cell that is based on biomimetic principles. To achieve these goals, UPC will chemically synthesize a panel of artificial building blocks that are designed to harvest light and/or tunnel electrons. When assembled into many different peptides, some of these constructs are expected to function as a diode, and, when linked to light-harvesting molecules, as a solar cell. Peptides will be embedded into a self-assembled monolayer of alkanethiols on individual gold pads of a computer chip, which will be designed and manufactured by IMS. Each individual peptide can be addressed by feeding in, and at the same time measuring, the amount of current flow in both directions through the gold pads of the individual pixels. A similar kind of screen should then detect a functional peptide-based solar cell. 10.000 Peptides per cm(+2) will be synthesized by a particle based combinatorial synthesis recently developed by KIT-G and PPP. These peptides will be transferred in the array format to the chip where they couple to the gold pads. Therein, peptides will be coupled through cysteine residues to the flat gold surface, where they are embedded into a membrane-like structure. We expect that our evolution inspired approach may open a novel route to very efficient, and very cheap solar cells. This is due to the small percolation distances, highly ordered modular peptide structures, the large number of generated peptides, the ability to easily combine and modify eventually found peptide-diodes, and the frugal material consumption.