Cornell researchers create much cheaper recipe for making solar cells

THE WOODLANDS, USA: The Dichtel group in the Department of Chemistry and Chemical Biology at Cornell University has developed a method to organize organic dyes into stacked sheets that are porous for incorporation into flexible solar cells.

The process could revolutionize the way solar cells are made by lowering costs dramatically, while creating highly-efficient and easy-to-manufacture 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 protected catechols 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. At the core of the framework are molecules called phthalocyanines, a class of common industrial 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.

This structure is a model that can significantly broaden the scope of materials that can be used in COFs. Once the framework is assembled, the pores between the molecular latticework could potentially be filled with another organic material to form light and flexible solar cells.

"This framework developed by Cornell researchers could possibly be one of the most significant advances in making solar energy more competitive with fossil fuels,” stated Robert Hines, president of Evolution Solar. “Also, advances like this could significantly lower up-front costs for solar power systems, which has been a deterrent for the industry that we would like to see disappear.”