> These kinds of cells require two well-matched organic molecules. The first, usually a polymer, absorbs light and produces excited charges. The second, usuall

> These kinds of cells require two well-matched organic molecules. The first, usually a polymer, absorbs light and produces excited charges. The second, usually a small molecule, pulls electrons from the first, allowing them to flow through electrodes so the cell can generate current. The challenge is that when chemists improve, say, the light absorption of the donor, its electronic properties may no longer pair well with the acceptor Sounds like an ideal problem for an evolutionary algorithm.