The Dichtel group in the Department of Chemistry and ChemicalBiology at CornellUniversity has developed a method to organize organic dyes intostacked, porous 2D sheets, which can later be incorporated into flexible solar cells.
The process employs organic dye molecules assembled into a structure known as a covalent organic framework (COF). The strategy uses a simple acid catalyst and relatively stable molecules called protectedcatechols to assemble key molecules into a neatly ordered 2D sheet.These sheets can be stacked on top of one another to form a lattice that provides pathways for charge to move through the material.
The best part of the process is that the reaction is reversible, soany errors that occur can be undone and corrected. At the core of theframework are molecules called phthalocyanines, a class of commonindustrial dyes used in products from blue jeans to ink pens.Phthalocyanines are also closely related in structure to chlorophyll,which absorbs almost the entire solar spectrum.
The structure by itself is not a solar cell yet, but it is a modelthat can significantly broaden the scope of materials that can be usedin COFs. Once the framework is assembled, the pores between themolecular latticework could potentially be filled with another organicmaterial to form light, flexible, highly efficient andeasy-to-manufacture solar cells.