Achievement

Silicon solar cells remain too expensive for many applications, while less expensive alternatives, such as organic solar cells, remain too inefficient. IGERT fellow Brian Koo and collaborators have used computational techniques to rapidly assay organic solar cells designs with novel and prototypical ordered heterojunctions, searching for designs that will push efficiency above 10%. Nanoscale ordered heterojunctions are fabricated "in silico" from covalent organic frameworks (COFs) – porous networks with predictable assembly and long-range order. To direct the growth of small molecules, COFs with different pore shapes and sizes were simulated. Using a combination of ab-initio, quantum calculations and molecular dynamics simulations, Brian determined the structural properties of 33 COFs, by far the largest computational study on COFs to date. He proposed a topology-based classification scheme for the stacking behavior of 2-dimensional COF layers.